If you find eBay Inc.'s TV commercials quirky, you should see its convention.

The third annual get-together of eBay buyers and sellers, held here last weekend, featured palm and tarot card readers, a wedding of folks who met on eBay, a collectibles treasure hunt, how-to-auction seminars and -- this is "Nawlins," after all -- an earful of live jazz.

But what really got the attendees wasn't the gospel singers marching down the aisle in white robes at the end of chief executive Meg Whitman's speech, waving eBay flags and belting out "When the Saints Go Marching In."

No, it was the eBay staff, more than 700 strong, who lined the exhibit hall to greet attendees with whooping, hollering and applause as they strolled in for the Saturday night gala. For days afterward, eBay dealers were still chattering on the auction site's message boards about how moving they had found the tribute.

You've got to hand it to eBay's leaders: They know how to play the crowd. The San Jose, Calif., company dispatched more than 10 percent of its 6,500 employees to the convention center to give 10,000 conference-goers a chance to connect with those who mind their auctions behind the computer screen.

It announced some new services for dealers, including a deal with GE Consumer Finance allowing sellers to offer installment credit to auction buyers through PayPal, eBay's electronic payment service. Also unveiled was software to help the 8,000 independent developers who create programs for eBay.

And Whitman said eBay had coughed up $11 million over the past year to fight fraud, including a new toolbar users can download to make sure they are transacting with eBay, rather than with a spoof site in Russia.

Yet eBay is experiencing other kinds of growing pains as it turns nine years old this year. Those, too, were on display as staffers fielded questions and complaints from the crowd of mostly sellers.

Dealers groused about a new billing system that went haywire two months ago, presenting many bills twice. Others fumed that eBay is too quick to take down auctions when any well-known manufacturer complains about how its brand name appears in items listed for sale. Still others said it was time eBay gave its high-volume dealers a break on auction fees, which have risen over the years.

But Whitman rejected that idea, vowing that eBay would continue charging every dealer the same rates, no matter how much they sell. She conceded it runs counter to traditional business, where high-volume buyers often get price breaks, but she made clear the online marketplace is wedded to providing "a level playing field for pricing."

Whitman said eBay will stick to that strategy even though one of its greatest challenges has been balancing the needs of small and large businesses as they auction goods side by side. She and others acknowledged, though, that eBay's roots lie more with the mom-and-pop entrepreneurs who helped create the Internet auction juggernaut. (The site has grown so massive, Whitman said, that it handles more daily trading traffic than the Nasdaq Stock Market.)

Conspicuously absent from the convention this year were the big-name manufacturers and retailers that eBay courted so aggressively in the past. EBay staffers said many dropped out after having trouble handling auctions in high volumes.

"A few years ago we tried to get big manufacturers and retailers to sell on the site," staff member Melinda Byerley told a roundtable of sellers on Friday. "We have backed away from that. Frankly, it didn't work."

Many trying to unload large quantities of identical goods on eBay, several dealers explained, discovered that online prices tend to fall as supply rises -- a well-known law of economics in the offline world. And as eBay continues attracting new dealers, competition grows fiercer.

"The margins are getting smaller on a lot of items," lamented Sheldon Wright, a pawnshop owner from Washington state.

James McHugo of Luxury Brands LLC, an exhibitor who supplies many eBay dealers with bulk lots, said he would not sell directly to consumers on eBay because of the logistical and price challenges. "One of the great fallacies of eBay is that it's easy," he said.

But eBay spokesman Hani Durzy noted that many big outfits still sell on eBay, including Sears, Roebuck and Co., which has three different eBay electronic storefronts. "It can be a great channel for a large company if they recognize how eBay works," he said.

EBay is drafting a new plan to court manufacturers and retailers by creating private marketplaces where they could hold auctions and invite select groups to come in and bid, such as their top 25 distributors, or the high-volume dealers eBay calls power sellers.

Randy Ching, a vice president who runs software development for eBay, said the company is testing auction software it bought from FairMarket Inc. last fall to explore new ways big businesses might liquidate their excess goods to eBay dealers.

"We'd like to invite power sellers in and give them an opportunity to purchase this inventory, often in large lots," Ching said. "EBay sellers could break it down into smaller lots and sell it. But manufacturers and retailers would determine who they would let into their private auctions, not eBay."

Many small entrepreneurs, who dominated the conference, said they're doing fine on their own.

Jerry Watterson, who runs a battery store and wholesale business in Jacksonville, Fla., said he has grown adept at finding new kinds of batteries to stay ahead of the "newbies" who often sell the same items at -- and sometimes below -- wholesale costs.

"EBay has been a terrific deal for us," Watterson said. "It will account for about half our business this year."

Leslie Walker's e-mail address is walker@washpost.com.