When we first reported on co-registration in 2001, it was the hot new way to grow your email house list without trying hard.

You simply stuck your opt-in offer as an extra check-box on another site's registration page or order form, and then they gave you the names of everyone who checked it. You paid on a per-name basis, or in some cases ran the campaign as a barter.

Loads of marketers including Hershey's, Travelocity, and cataloguer Sierra Trading Post tested co-registration. Unfortunately so many of these campaigns did badly -- pouring worthless trash names into marketer's house files -- that co-registration fell out of favor.

Sierra's Online Marketing Coordinator Leigh Vosler admits, "It did poorly for us."

Why?

Michael Lastoria, CEO Innovation Ads, a boutique agency specializing in co-registration campaigns, explains, "A lot of people have been burned buying names at ridiculously low prices from sites that threw offers up there on a churn and burn model."

But now co-registration is coming back into favor again with marketers including Oracle, New Balance, USAToday, and yes even Sierra Trading Post. (See link below to campaign samples from all.)

Plus there's good news -- you can pre-qualify prospects so you get higher-quality names, and cost-per-name still ranges in about $1 per. That's cheaper than you can possibly get a lead from search marketing, even at below-average CPCs and above-average conversions to email sign-up.

Here's our quick "201" report on how you can take advantage of the co-registration boom before prices rise too far:

Best practices in co-registration three-step strategy -- don't put names directly into your house file

"Fortune 1000 marketers typically just throw the names in their database. You can burn through $100,000-150,000 pretty quickly doing that and have data that's pretty much worthless," notes Lastoria.

In fact, that's about what everyone we knew conducting co-registration campaigns a few years ago did. You piled the new names into your house list and mailed them your regular stuff until they hard bounced or unsubscribed.

Best practices now say you should isolate co-registration names from your house list. Keep the files separate, or at least code name origin scrupulously so you can segment, mail, and track them separately. Two reasons:

o Generate conversions first

Just because someone ticked a box on a third party site to get your email doesn't mean they are ready to enter into a full-throttle relationship with you. You need to send a series of emails (and possibly snail mail and/or telemarketing) that's specifically designed to convert them into first-time buyers or qualified, hand-raising sales leads.

These emails should have different creative and timing from your regular campaigns. You'll want to test what works best to convert co-registrations (more below). Then you can move the names to your house list and begin the more traditional ongoing relationship.

o Safety

You'll be far safer if you use a separate IP address and possibly a separate broadcast vendor to send out mail to these names.

Although these names are opt-ins, they didn't opt-in at your site nor have they purchased from you. They are more likely to forget that they asked to receive email from you. They are more likely to register spam complaints. Don't let these potential complaints impact delivery for your main house-file sends.

So the strategy is three-step. Get the opt-in, market repeatedly to a name until it converts into a true relationship, and then move the name to your regular house file.

The three elements of co-registration campaigns:

Just as with any other campaign, you should be testing each of these elements to see what works best for you.

Element #1. Media Buying

Lastoria recommends you test at least five-ten sites with test cells of 10-20,000 received names each. Sierra Trading Post's Leigh Vosler told us she considered 5,000 names per site plenty.

The problem is you probably won't know for a long time whether a particular test pans out. Sierra's test cells took an average of 80-days to reach profitability. In the meantime you don't want to turn off campaigns to wait, because you're sacrificing potential income.

Plus, now that co-registration is more popular, it can be hard to get a place at the top sites. These accept only a handful (usually five-seven) of offers at a time, and you may have to book your slot up to three months in advance.

We recommend that you review co-registration name attributes carefully, including average opens, clicks, and quality of earliest converters, to see if anything indicates success or failure early on.

This is similar to postal direct mailers who roll out test lists using "doubling dates" -- the early date at which you can guesstimate from initial responses what the list response as a whole will be.

Other media buying tips:

- You can negotiate to only pay for names that are not duplicates with your current house file. - Only pay for email and/or postal addresses that are verified as being accurate and usable.

- Always, always, always personally look at every site your offer will be placed on. Don't take the media sales rep's assurances that "Oh yes this is opt-in" at face value. Never buy at a site that pre-checks boxes, has an iffy-sounding privacy policy, or just "feels wrong" for your brand.

- Unless the site is a very famous name, don't buy co-registrations if there are too many offers cluttering the page already. More than 7-10 offers and people don't click carefully. These names won't be high quality.

Element #2. Creative

Your creative consists of a logo (generally 120x60 but some sites ask for 80x60) and about 250 characters of copy including white space.

Sometimes you can add a bit more by putting a user-generated pop in. USAToday does this on a few sites where their copy says "more info" and then a little box comes up with that info. (Link to sample below.) Don't count on most site owners allowing this, and certainly don't count on users clicking on the link to view it. Most won't.

Lastoria recommends you test copy to see which pulls the best opt-ins for your program. However, "best" doesn't equal "highest volume." You want names that will convert, the rest are just a budget-suck.

He's tested putting qualifiers in copy to weed out the non-responders, such as:

o You most be 18 with a major credit card living in these states to qualify.

o Are you a busy mom?

o Do you ever attend Yankee's games (or wish you could)?

o Do not check this box unless you suffer from...

Element #3. Autoresponders and other follow-ups

An autoresponder is an emailed message that's pre-written and loaded into the sending computer. It's then automatically sent out to names based on an event or date-trigger.

A welcome message is an autoresponder - a message that's sent to new names when they are added to a list.

Lastoria recommends you create (and test the living daylights out of) an autoresponder series for your incoming co-registration names. The Welcome message should, if possible, reference the site the name signed up at. A Welcome can also feature a special offer to entice early converters or get names to fill out additional demographic info on a survey form.

Then you can use the rest of your autoresponder messages to do either of the following:

o Educate prospects until they understand your offering enough to purchase it. This could be as simple as a series of white paper and webinar offers or perhaps an e-course.

o Present a series of enticing offers until the reader crumbles. This works well for impulse buys, as well as things people tend to buy only a few times a year.

Don't just send these names your regular email newsletter though. People on your newsletter list are probably in the middle of a relationship with you. Names from co-registration are just starting out. They deserve a "starter's kit" of special emails just for their needs.

Test the number of autoresponders you send until you dump a name as a non-responder. Some marketers send dozens. Also test the creative of each autoresponder, and of course, autoresponder timing.

For example, Lastoria learned through relentless testing that one client's names converted best if they received 30 autoresponders in a row, one a day for 31 days. Why 31 days? Turns out sales went up if they skipped sending day 19. Weird but true.

Sierra Trading Post tested combining a series of email autoresponders featuring their best recent sales offers with printed catalog mailings to the same lists. Best timing - one email every 10 days and a monthly catalog.

Four types of b-to-c co-registration sources:

Not all sites offer co-registration, but an increasing number are considering it. Lastoria breaks them into four groups for easy reference...

Tier #1. Big name brand sites

These include NYTimes.com, Weather.com, CBSMarketWatch, etc. Because they are household brand names, your brand may get a lift just from being visibly seen as a "partner" logo on their registration form. So they charge a bit more, generally $1 per name or more.

Because they are so famous, they don't get a lot of new registrants (most folks who are going to sign up, probably did so already), so you can't get enormously high volumes of names from these sites. If you need tens of thousands tomorrow, you need to include another tier in your media buy.

Also, they tend to only offer a few slots, and those slots get sold out early. Plan ahead.

Last but not least, these guys are picky about who they partner with. Your brand can't be seen as detrimental to theirs.

Tier #2. Niche and vertical sites

These include Regards.com, Neopets.com, and other sites that are popular among their users, and may get more traffic than you think.

You're not buying famous brand, so prices can be as low as half of what you'd pay for the big boys. Name quality may be surprisingly high. Many of these sites don't take co-registration... yet. A media buyer can persuade them if you're willing to pony up with a firm promise once the test is run.

Sierra Trading Post's best co-reg sites were in this category. Names from the very targeted Trails.com converted to profitability in just 10-15 days instead of 80.

Tier #3. Survey sites

You know all that junk mail you get from "surveys" and "researchers" you've never heard of asking for your opinion? Chances are they're making their money by selling co-registrations.

They use the survey questions to figure out which offers fit the prospect the best, and then offer them. It's targeted, but their methods of traffic generation aren't always best practices.

Ask where traffic comes from prior to signing up to work with a survey site. Costs can range from $.35-.50. Any lower and they are definitely spammers - so stay away.

Tier #4. Free offer and sweeps sites

There are dozens of these online, ranging from jackpot.com, hitthejackpot.com, etraveluniverse.com, ezsweeps.com, etc.

Often owned by individual entrepreneurs, they spend hundreds of thousands in banners, text links, and search marketing each month to get more traffic. They profit by selling co-registrations.

While many used to be spammers, the tactic's just too risky these days. They may mail their own house list, but won't rent outside lists. (Be sure to ask where the traffic comes from though.)

Again pricing is around $.35-.50. The good news is these sites can send you high volume. If you need hundreds of thousands of names or even millions to mine for conversions, this is the quickest and easiest way to get them. It's a heck of a lot cheaper than search marketing and less dangerous than renting lower-cost email lists yourself.

Three types of b-to-b co-registration sources:

It's a bit harder for b-to-b marketers to buy co-registrations but not impossible. We've heard of three sources:

Source #1. Controlled circulation networks

Two vendors run online networks gathering business executive names for print magazines -- Synapse Group's FreeBizMags.com and The Subscription Network. They place offers on a wide number of b-to-b sites, and then ask clickers to answer a long list of questions to qualify to receive targeted trade magazines for free.

Generally they sell co-registrations from this system for about $5-8 a pop. But this includes snail mail address and often even phone as well as email. And you can target by title, zip, industry, etc.

We don't know of many b-to-b marketers who are using these networks yet, but it could be done quite easily.

Source #2. Creating your own third-party site

We know several b-to-b marketers who've gone this route. They got together with several complementary vendors in their same field and created an educational site for the industry. It can contain articles, a white paper library, or a glossary, or even a special offer such as a sweeps.

All partners work together sending email campaigns to their own house files to visit this new site. Then all benefit from resulting registration opt-ins. An example of such a site is The CFO project.

Source #3. Special offers to business news sites

Although many trade magazines are still mired in the print-past and refuse to consider co-registration (often the ad sales reps haven't even heard of it), some publications are testing ideas.

For example, The Economist has offered a co-registration program for more than a year now to such advertisers as Oracle. In this case you purchase "complimentary Economist subscriptions" and they send out an offer to their opt-in list of free readers asking folks to sign up - handing over their email address to you - to get into the paid site. (See sample below.)

Costs will vary depending on the site.

Useful links related to this article:

Creative samples - how co-reg offers from Sierra Trading Post, Oracle, New Balance, and USAToday appear on the Web: http://www.marketingsherpa.com/coreg/ad.html

The CFO project http://www.cfoproject.com

Info on Synapse Group's Free Biz Magazines.com & The Subscription Network http://www.contentbiz.com/bizblog.cfm?ID=21

Innovation Ads http://www.innovationads.com

Sierra Trading Post http://www.sierratradingpost.com