Donald Trump, who likes to do things big, must be pleased by Thursday's premiere of his new reality show ''The Apprentice.'' An average of 18.5 million viewers tuned in to watch the would-be executives compete for a $250,000 job working for The Donald, making ''Apprentice'' the highest-rated series debut since ''Joe Millionaire'' a year ago. It wasn't a big enough number to knock off perennial Thursday-night winner ''CSI: Crime Scene Investigation'' (whose 9 p.m. episode on CBS took viewers away from NBC during the last third of the 80-minute premiere, drawing a total of 27.5 million), but it was strong enough to lead NBC to program two episodes this week: one in its regular Wednesday time slot and another on Thursday between ''Friends'' and ''Will & Grace.''
The first episode's lemonade-stand challenge saw constestant Kristi Frank lead the women's team to victory, as she sold drinks by offering customers pecks on the cheek and even her phone number. Frank, whose official NBC bio lists her as a Santa Monica restaurateur and former blackjack dealer, has some experience using her sex appeal to make money; according to TV's ''Inside Edition,'' she's also a former softcore actress, having starred in the ''Swimming Naked'' episode of Showtime's ''Red Shoe Diaries.'' (In that episode, she can be seen, well, swimming naked.) ''You putting it on TV can only help my ratings,'' producer Mark Burnett told ''Inside Edition,'' noting that he was already aware of Frank's frank past. ''I wasn't sure how long it would take you to find out. I should have called you myself.'' While a porn past embarrassed ''Joe Millionaire'' contestant Sarah Kozer and led to the ejection of ''American Idol'' finalist Frenchie Davis, it certainly hasn't been an impediment before on a Burnett-produced reality contest; skinflick star-turned-car dealer Brian Heidik won the $1 million jackpot on ''Survivor: Thailand.''