Following the model of Interactive Imaginations' Riddler, New York, Oakland, Calif.-based Play4Prizes signed Berkeley Systems, Match.com, Women's Wire and WhoWhere? as advertisers on a site offering online puzzles in which sponsor sites provide clues.
Advertisers that sign on to Play4Prizes (http://www.play4prizes.
com) before Sept. 22 pay 15 cents for each visit to their site; after that, rates are 25 cents per visit.
Play4Prizes' system "gets people to come in and look around," said Lenore Tuttle-Wilkas, director of advertising for WhoWhere?, an Internet e-mail address directory (http://www.whowhere.com).
Registered players who correctly solve at least one puzzle are entered in a weekly drawing for cash prizes that currently range from $25 to $250. "The more traffic we get, the larger the prizes," said Sharon Vinick, Play4Prizes' president-chief operating officer.
Riddler (http://www.riddler.com), which has been running contests for more than a year, takes a different approach: Sponsors including Toyota Motor Sales USA and Quaker Oats Co.'s Snapple provide the prizes. Riddler has more than 125,000 registered users.