ezboard, a 1998 startup, used Smalltalk for their bulletin board service. They did really well for awhile but have been declining steadily ever since 2003. Apparently they couldn't figure out how to make money from the sites with heavy traffic. After some unpopular decisions about pricing and advertising, many of their biggest customers decided to host their own boards instead, using solutions like vBulletin or phpBB.

ezboard had several different subscriber levels. The free version caused your board to be so full of popups and other intrusive ads as to be almost unusable. It was worse than Myspace (and Firefox wasn't very popular yet). The first paid level let you turn off the popups but left the banners, including a huge banner at the bottom so that if you hit the "end" key to see the latest comment you'd wind up with a banner in your face and would have to scroll back up to see the comments. The premium level let you turn off all ads, but it was more expensive to do that than simply hosting your own solution.

They still exist, but I haven't really been paying attention. I'm not sure if they still use Smalltalk or not.

http://en.wikipedia.org/wiki/Ezboard