11.   American has become willing to offer even lower fares on sites like Priceline than it had originally intended.

12.   Among them was a proportional counter, known as the Rossi counter, which measures the energy deposited by radiation in microscopic sites like cells.

13.   Among airlines like American, which was not an early participant, sites like Priceline have won a growing allegiance.

14.   An early case in point may be coming from e-tailers and their relationships with portal sites like Yahoo, America Online and others.

15.   An industry of entrepreneurs has sprung up around auction sites like eBay.

16.   And a plethora of niche sites like gunbroker.com, planet bike and mobilia.com, for car buffs, are proliferating.

17.   And although sites like Motley Fool have long provided a forum for investment club members, the new sites take the clubs one step further.

18.   And so far, health-care sites like Drkoop.com have struggled with ballooning losses and wary investors.

19.   And so far, major news sites like CNN.com and MSNBC.com seem to take a much more proprietary view of their content and how their audiences use it.

20.   And while nearly all purchases from online stores are made by credit card, many buyers on person-to-person auction sites like Ebay, are made by check.