The 5 percent rebate applies to purchases made during the 1998-99 fiscal year at any of the six Coop locations as well as purchases made from its on-line catalogs.

Coop members from the Class of 1999 don't have to worry about getting their share, Murphy said.

"We try to notify [the graduated seniors] of their check through e-mail and alumni associations. Most of them get around to cashing it," he said.

he Coop attributed its profits last year to strong book sales at their Harvard Square location and increased orders from their Web-based catalog. In addition, Murphy said Coop membership has been expanding significantly both among students and alumni.

According to Murphy, competition from the on-line market for textbooks has not yet had a major impact on Coop sales.

While undergraduate mail centers continue to receive packages of books from on-line sites, Murphy maintains that many students have found that it is "not worth the small difference in price" to shop on-line compared to the convenience of shopping and returning books from the Square's store.

And after factoring in the costs of shipping and the added bonus of the annual rebate, the Coop's prices were competitive with other vendors, Murphy said.