Signature blocks, those lines of text some people include at the bottom of their email messages, are as old as the web itself. Some of the earliest emails included primitive signatures; perhaps Major Raymond Czahor earns the dual honor of first email signature and first screamed message: “CHIEF, ARPANET MANAGEMENT BRANCH, DCA”. Plain vanilla signatures include name, title, company, and contact info. Interesting ones contain jokes, quotes, and other colorful items that convey something unique about the sender.

The signature is our most common personal billboard. And yet, oddly, it’s among the least developed. This is true not just for email, but instant messaging, SMS, and forums. So my idea? Give people an easy way to make their signature blocks a lot more interesting and useful. Let’s call this hypothetical service MailTail.

MailTail would automatically insert content from categories a user chooses: jokes, quotes, icons, photos, links, news, tips, horoscopes, stock quotes, and more. Where possible, the user could screen, rate, and delete signatures, creating data on what individual and aggregate users like.

MailTail first release (alpha) could be a web service, toolbar, social network app, or mobile app. Some services like Yahoo Mail and Google Talk offer application programming interfaces (APIs) to edit signatures and status messages, while other services would require hacks to access the end of an email, text message, forum post, or IM status.

A billion people use email and instant messaging; communication is the #2 activity on the web behind visiting websites, so there’s no shortage of potential users of another service like this that would offer brief, non-essential messages. There are other signs MailTail could be popular: the growth of micro-message tools like Twitter, data APIs to push and pull content, email enhancements like Xobni and Xoopit, and content-sharing apps like Facebook’s Bumper Sticker. If porn is the first application of new technologies, exhibitionism might be the second (which is strangely symmetrical).

Later stages of the MailTail product could insert dynamic content such as the user’s recent blog posts, pictures, bookmarks, tweets, and location; Gnip would make it easy to get such data. Business users and IT departments might want to enhance signatures with logos, legal disclaimers, news, surveys, and digital business cards. It sounds trivial, but Yammer is charging over 2,000 companies $1-5/employee by enhancing business micro-messages.

Users could also opt to send and receive signature links from friends, which could increase serendipity and no doubt lead to some shenanigans. At scale, the company could create a platform that connects message senders and publishers, letting anyone upload and distribute potential signatures. It’d be a Digg that comes to you.

The service could make money off sponsored signatures and premium features. StumbleUpon steers users to sponsored advertisers and Bumper Sticker co-founder Maisy Samuelson says companies paid tens of thousands of dollars to promote stickers. Users could opt to insert ads — Hotmail inserts them with no user incentives — but it’s unlikely people would do so even with a revenue share given the small returns. Click-thrus for AdSense ads suck despite keyword-targeting because they’re impersonal and often irrelevant.

What could work are social ads like Facebook’s Beacon: items the user recently bought or rated, music or movies the user likes, and other tastes that say something about both the sender and the advertiser. Premium features could include virtual gifts, custom logos and avatars, and analytics on what users are sending and clicking. Incredimail has built a $40 million company with simpler features.

There are few direct competitors in this space with traction. Incredimail has a lot of users but requires a download. Plaxo has a business card feature but it didn’t take off. WiseStamp has few downloads and features. A few other startups have poked around the online business card space but none have gotten far. Gmail has a random signature feature, but it’s limited to quotes and is little used. Outlook and messaging systems might create this themselves, but they’d likely serve only their own product and probably have higher-priority features.

I think the key question is whether people want this enough to adopt a service or toolbar. Inserted content could be seen as helpful or intrusive depending on context and quality. People can be picky about their sign-offs, and too many unwanted signatures would turn users away.

Gauging demand shouldn’t be hard. A team could build a basic MailTail in a few weeks and kill it if there’s no adoption. It’s counter-intuitive, but market risk is often better than marketing risk. It wasn’t clear people wanted to broadcast their lunch in 140 characters, but the Twitter guys knew their product would spread virally if they did.

And this is where MailTail shines. It has the killer feature of inherent one-to-many virality: Every user message can include a subtle sign-up link. With roughly 2.5 billion text messages, 12 billion instant messages, and 210 billion emails sent every day, even a miniscule number of users and viral conversions could drive hyper growth. This is the same viral loop that made Hotmail one of the web’s fastest growing companies not named Skype or Youtube.

That may be the real value in this idea — not that people want better signatures, but that millions of messages are sent every day with unused space. Clever entrepreneurs will find ways to use it.

What do you think?

 

 

Do you think MailTail is a good startup idea?(web polls)
If you missed my previous “What’s Next” posts, follow the links:

 

What’s Next: Free computers for small businesses?
What’s Next: A butler for your idle computer?

Mark Goldenson is starting an innovative web venture in health care. To submit an idea for the What’s Next series, email Mark at mjgold3@gmail.com. Selected ideas will receive attribution.