It's never too late to teach an online brokerage some Web 2.0 tricks.

E*TRADE (Nasdaq: ETFC) is launching E*TRADE Community, a social-networking platform for investors.

Registered users must have retail brokerage accounts with the discounter to actively participate in the hub.

E*TRADE Community members will be able to gauge market sentiment and share stock ideas and opinion. Members can follow other members and share recent trading activity.

The concept isn't entirely new. It has shades of TheStreet.com's (Nasdaq: TST) Stockpickr and our own Motley Fool CAPS, where the "wisdom of crowds" cultivates a more knowledgeable base of individual investors. Larger rivals Charles Schwab (Nasdaq: SCHW) and TD AMERITRADE (Nasdaq: AMTD) -- and niche specialists optionsXpress (Nasdaq: OXPS) and Interactive Brokers (Nasdaq: IBKR) -- arm their accounts with plenty of Web-based research tools, but don't necessarily want them getting chatty with one another. Zecco is the exception here. It's been blending an investment community with marked-down brokerage services for years.

If this works, E*TRADE rocks. A hub of accountable investors sharing ideas and profiting from picking fresh brains should not only succeed on Wall Street but also generate a ton of commissionable trades for the broker.

This isn't a slam dunk, though.

E*TRADE closed out 2010 with 4.2 million customer accounts, so populating the community shouldn't be a problem. The real challenge will be if the folks who become part of the fabric are willing to trade in their anonymity.

E*TRADE Community isn't requiring members to register with their real names or reveal too much in their profiles. However, opinions may be held closer to the vest when participants realize that their online actions can be traced back to a real trading account. This is a beautiful thing on the surface. No more shenanigans, pumping from multiple accounts, or spiteful flame wars.  

Nice!

However, if limiting participation to eligible brokerage account clients and Orwellian fears of the E*TRADE Baby watching over you result in a small base of active participants, the "wisdom of the crowds" becomes the "groupthink of the few."

What's that? You're still unsure about whether you should get a new broker? Get thee to our Discount Broker Center to learn more and compare some sponsored commission schedules.

Interactive Brokers Group, optionsXpress Holdings, and Charles Schwab are Motley Fool Stock Advisor picks. The Fool owns shares of Interactive Brokers Group. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors.

Longtime Fool contributor Rick Munarriz has been trading exclusively through discount brokers since 1990, but he does not own shares in any of the companies in this story. He is also part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early. The Fool has a disclosure policy.