1.   Existing companies-bookstores, for example-are taking defensive action against online retailers.

2.   Shipping costs can cut deeply into the discounts offered by online retailers.

3.   Among Internet companies, stock investors have rewarded Yahoo, which announced Tuesday that in contrast to many online retailers, its holiday sales had doubled over last year.

4.   Amazon.com, the online retailer, is one of the most obvious examples of that.

5.   Amazon.com executives and analysts agree that the online retailer must keep costs down while encouraging consumers to open their wallets.

6.   Amazon.com, the online retailer that already dominates Internet sales of books and, increasingly, music, is about to start offering a much broader array of merchandise.

7.   Among them are Toysmart.com, the online retailer, and Reel.com, the movie video retailer.

8.   Analysts said the audit foreshadowed challenges that would be faced by online retailers in general as narrow margins fail to compensate for marketing costs.

9.   Analysts predict that online retailers may have to wait a while longer for the financial markets to improve.

10.   Analysts said that in concept, at least, the prospects for an online retailer of educational toys are promising.