Many financial institutions' main Web sites include microsites — pages that promote a specific product or service. They're not too flashy or innovative, not too expensive, not too taxing on the technology department and certainly present no threat of overshadowing the banks' primary sites.

But at some institutions these sites are becoming major undertakings. SunTrust Banks Inc. of Atlanta and GTE Federal Credit Union in Tampa have overhauled their microsite strategy to focus on a specific market segment instead of a product. The pages often downplay ties to the financial institution, incorporate social media, can often drive traffic through live events and attract new customers.

And they're much bigger and more expensive. Instead of five to 10 pages, they're 50 to 100. The microsite has become a megasite.

"The strategy with megasites is to create a deeply immersive experience, and they're throwing everything at it: social networking, Internet banking, blogging," said Jeffrey Pilcher, a consultant and publisher of The Financial Brand.com. He said megasites, while appealing, raise questions for banks and other financial institutions. How far can they stretch their tech resources, in terms of time, money and expertise? How do they integrate social media sites? How do they maintain brand cohesion between their main site, megasites and microsites?

Doug Richardson, a senior vice president of marketing at GTE Federal, was instrumental in conceiving and launching the credit union's U224U.com Web site that targets customers and potential customers ages 12 to 22. When he took the idea to the internal tech team, he quickly realized they did not have the time or the ability to construct a site that incorporated Facebook and YouTube.

So he turned to an outside agency, CAE Marketing Group, which for $60,000 got the site ready within 60 days.

It launched in July and Richardson said it has resulted in 2,700 new accounts and a 10% annual growth rate among people 12 to 22. He attributes the success in part to engaging online contests tied to offline events. The site has been so successful the credit union is developing megasites for other member segments.

SunTrust launched a megasite in November called LiveSolid.com. It provides hundreds of tools, calculators, articles, guides, videos, podcasts and tips designed to help people make informed financial decisions. Like GTE Federal, SunTrust had an outside agency to design the site and incorporate social networking aspects. Broud Kuhn, SunTrust's group vice president of digital and direct marketing, said the project took about five months.

The success of U224U and LiveSolid leads Pilcher to wonder if the megasites of today are the home sites of tomorrow.

"Right now these Web sites are experiments, but if they are more effective why not use this as their home page? These could be what the online bank of the future looks like."

Kuhn says the future is probably somewhere between today's megasites and conventional home pages. After all, one of a megasite's greatest strengths — its ability to target a certain customer segment — becomes a weakness if the bank is trying to appeal to everyone.