WAYNE, N.J. — A 21-year-old college business major living in this northern New Jersey community has proven a basic lesson of marketing: Sex sells. Courtney Van Dunk posted a bikini-clad picture of herself on eBay about two weeks ago, auctioning off space on her body for advertisers.

The auction ended Thursday with a winning bid from a New Jersey wine retailer offering $11,300 for a month’s worth of advertising. Van Dunk, though, says the offer has been retracted, but she’s confident that she’s made contacts with enough companies to still earn some cash.

When she finds a buyer, Van Dunk plans to place temporary tattoos on her abdomen while she’s at the beach, or on other body parts when she’s at the mall, sporting events, amusement parks and other public places. Her butt and chest are off limits.

“I got the idea from a marketing class I had that did a short segment on body advertising,” Van Dunk said. “I was wondering how advertising could get through to our TV-savvy generation, and I thought this would be an excellent way to do it.” Van Dunk says the first round of bidding drew inquiries from as far away as Zambia. The Web site halted that auction because she had links to other sites promoting her efforts, so Van Dunk then held a second auction, which lasted seven days.

Van Dunk credits moderate exercise and healthy eating for the fit figure that has earned worldwide interest.

“We never ate a lot of fast food or greasy things growing up. My mom is an excellent cook. I really owe a lot to my parents for that,” Van Dunk said.