Still, some artists have scored big sales through the Saatchi Web site. One of them is Regine Freise, a set and stage designer from Berlin. Freise says her realistic portraits had been turned down by at least 40 Berlin galleries before she posted a few on Saatchi's site in May. Within 24 hours, she had sold one, "Teabreak," for around $1,300. She has since sold two other paintings. "I'm just amazed," she says.

Jeffrey Neuenschwander, who bought "Teabreak," has bought five paintings via Saatchi Online in the past year. "I still like going to galleries, but online, you can scroll through 500 or 600 artists in an evening and see a large cross-section of work," he says. (He typically asks artists to email him several images of work he's interested in so he can better judge color and scale.)

Other artists say the site's exposure hasn't reliably translated into sales. Changwoo Ryu, a London-based artist, was ranked first in a weekly "Top 10" artist roundup on the site in May but says no buyers have surfaced. Charlene Weisler, an artist in Manhattan, says her Saatchi page led to an invitation to exhibit her street-graffiti photographs in a city apartment that was also on the market, but she says no collectors have bought her work yet via the site.

While many other art-selling Web sites often charge gallery-like commissions, Saatchi Online's nonprofit extension, launched in May 2006, allows artists to sign up free and create tailored home pages on the site featuring their artwork and resumes. Artists are free to field email inquiries from any potential buyers visiting their pages, and they can keep all proceeds from any art sales. Buyers, in turn, can shop around the clock for contemporary art made world-wide.

The artists post images of everything from rudimentary sketches of nudes to wall-size paintings by gallery veterans. Separate areas on the site are reserved for art students and children who want to display their art. (Saatchi has held onto a portion of his original Web site as a way to catalog his own private art collection.) Saatchi says he is still trying to introduce elements to help more of the site's artists stand out. On Monday, he unveiled a PayPal-assisted, click-and-buy feature called Saleroom, and within the next year he plans to translate site pages into Portuguese and Russian. (The site is already offered in Mandarin.)

But Saatchi concedes the venture still has some distance to go before it can truly compete with the experience of buying art in person. In fact, he himself usually arranges to borrow potential art purchases so he can see them in person first. However, he says next month marks an end to his self-imposed restriction against buying work from his own site.

Dealers say they don't feel threatened. Mary Leigh Cherry, a Los Angeles dealer, says she has no plans to hunt for prospective artist clients on art-selling sites. "There are just so many active artists already out there," she says. "The market can only absorb so much."

Nicole Asendorf, a recent art-school graduate from Cottekill, N.Y., posted her work on Saatchi's site over a year ago. In March, she found her first taker: Ugallery.com, another online art-selling site, which has since signed her to a contract to use their site to sell her abstract paintings for anywhere from $20 to $1,200 apiece. (Ugallery gets an undisclosed cut of her proceeds.) Total sales so far: just over $1,200 for 54 paintings, she says, adding, "I just want my stuff to sell."