Perhaps the best new-economy lesson from the last six months is this: Take new-economy lessons with a grain of salt. When Phil Carpenter's eBrands: Building an Internet Business at Breakneck Speed came out last summer, it had star backing. On the dust jacket, Pets.com CEO Julie Wainwright sang Carpenter's praises, while Priceline.com founder Jay Walker called the book "the perfect primer" for the new economics of marketing. Six months later, Pets.com is dead and Walker's business is stumbling.

When eBrands hit bookstores, one of the case studies, Onsale, had already been bought by Egghead. In desperate straits, CDnow and Fogdog soon followed. IVillage is limping; even Yahoo's been hurt. "The market's telling them they should have been spending money more judiciously," Carpenter now says.

He has a new chance to test his theories. When eBrands came out he was working at Remarq, soon bought by Critical Path. Now, he's the marketing VP at travel site Sidestep, working to build awareness through media coverage, not expensive ads. Sounds good now, but check back in six months.