Remember Mercata? The Bellevue "we commerce" company that raised tons of cash from billionaire Paul Allen during the dot-com boom -- then filed for an $100 million IPO in 2000 -- before crashing a year later.

Well, some ideas just never die. Groupon, a Chicago startup, is trying to resurrect the idea of group buying online.

On the surface, the concept doesn't seem that bad since it is rooted in some traditional retailing practicies: The more people who want to buy a specific product or service, the cheaper deal they can negotiate.

It looks as if the founder of Groupon, Andrew Mason, has at least studied the failures of the past.

“The sites in the first dot-com boom were competing against Wal-Mart and Amazon for consumer goods and electronics,” Mason tells The New York Times. “And then you’d have to wait two weeks for an item that wasn’t much cheaper than if you’d driven to buy it yourself.”

In fact, in a post-mortem story I wrote on Mercata an analyst pointed out that very same problem noting that the deals just weren't waiting for. Another analyst said the concept of group buying was just too foreign to consumers.

Instead of following the Mercata path, Groupon is focusing on smaller local service providers in 24 cities, including Seattle and Portland.

For example, the Seattle site now offers a 67 percent discount on Rain City Yoga classes in the University District. The auction -- which 149 people have participated in so far -- has 12 hours left.

It would be interesting if TeachStreet -- which is compiling a directory of local teachers -- headed in this direction too.

At the time of Mercata's demise, CEO Tom Van Horn told me that there wasn't anything wrong with the business model itself, blaming the tough economic conditions instead.

Groupon hopes that's the case, and appears to have learned a few things along the way. And here's one lesson you can't really contro: Timing is everything.