Sold out - or is it?

Suppose your sole summer goal involves rocking out with the Rolling Stones.

And forget the nosebleeds - you want to be able to count the lines on Keith Richards's face.

Ah, but you possess pockets of average depth. And you feel the need to eat every once in a while, maybe even tank up the Toyota.

Sing along, superfan: You can't always get what you want.

Onstage box seats for last Sunday's Fenway Park show - the first stop on the Stones' world tour - went for more than $3,000, 12 times their face value, at TicketsNow.com. That's no anomaly. In what's being called the biggest summer of A-list concert tours in a decade, supply and demand have kicked into overdrive.

But in general - whether for the Rolling Stones, Dolly Parton, or a Major League Baseball game between division rivals - "sold out" doesn't always mean that there are no seats available.

Quick "sellouts" often just reflect rapid dispersal of tickets into the vast and nebulous secondary market, whose players range from licensed online brokers to street-corner scalpers flouting often poorly enforced laws. The legal segment of that market alone has now eclipsed primary-sales colossus Ticketmaster in annual dollar volume, according to some industry experts. And while all of that churn might be confusing to buyers, it can also open opportunities for those who know where to look (and that doesn't mean playing into the scalpers' game).

The Monitor bought a Rolling Stones ticket at face value from a primary ticketer 10 days before the Sunday show. We found opportunities to do so even later (for singles, granted, and far from the stage).

But plumbing the secondary market is as tricky as defining it.

"Anybody with a ticket is now a 'ticket broker,' so how you describe the secondary market is becoming blurry," says Gary Adler, a spokesman for the National Association of Ticket Brokers, which advances a code of ethics among its members.

By some accounts, nearly a third of event tickets sold are resold through the legitimate secondary market. The number balloons when the peer-to-peer element is included.

Craigslist.org, for example, opened its ticket section in July 2000. It reached around 10,000 a month in April 2002, according to Craig Newmark, founder of the free online classified site, and is now running at about 120,000 a month, thanks to the site's expansion into new cities.

Even though concert ticket sales have slid overall, resale activity has picked up in recent years for top acts with baby-boomer appeal, say industry experts, driven by the public's rising comfort level with online transactions, whether with recognized entities or with other individuals.

Another factor: frustration with major primary outlets like Ticketron and Ticketmaster, whose inventory, meted out as dictated by the venues, seems to vanish within minutes of going on sale - at stadium box offices and music stores, via telephone sales and the Internet.

The abundance of ticket outlets "doesn't actually make [getting tickets] more competitive" for buyers, maintains Bonnie Poindexter, a Ticketmaster spokeswoman, though "it makes it more convenient."

Including sports and other events, Ticketmaster sold 98 million tickets valued at $5 billion last year. It uses optical barriers - digitized codes on their website to prohibit automated buying - and other means to complicate mass purchasing by resellers, but Ms. Poindexter acknowledges limits to ensuring broad access.

"We're not the ticket police," she says. "We can't look at a row of people in line and say, 'You look like you're going to resell your ticket, therefore we're not going to sell to you.' "

As it is, in terms of primary sales, as many as half of a venue's seats might be spoken for at a major show - with comps given to radio stations, corporate sponsors, and the band, among others.

Through some of these channels, though, fans can get the inside track on tickets. These include fan-club membership discounts, corporate-affiliation deals (with your credit-card company, for example), or charities who give tickets in exchange for large tax-free donations or a few hours of community service. But beware, would-be profiteers, too, can scoop up seats from these same channels.

Also making gains: big-volume licensed brokers, which don't own inventory but rather facilitate sales by private parties whose tickets are screened for validity. The brokerages' revenues are percentage-based.

"We get discounts from the seller, and then there's a service charge to the buyer," says Kenneth Dotson, chief marketing officer for Tickets-Now.com, who calls the legitimate secondary market a $6 billion a year business (other estimates make it considerably smaller).

Professional baseball, Mr. Dotson says, pulls in the most revenue. Sports events represent more than 50 percent of his firm's business, then concerts, then plays. "'Wicked' and 'Spamalot' are really big sellers for us," he says, adding that tours by Paul McCartney, U2, and the Rolling Stones have set this year apart. TicketsNow guarantees transactions and requires that its sellers be licensed brokers.

Other online marketplaces enable ordinary fans to wheel and deal. Ticketmaster, for example, allows season-ticket holders in more than 30 sports venues to sell tickets they are unable to use through the TeamExchange program, a "team-sanctioned legitimate secondary marketplace" launched in 2002. The idea: Teams can add value to their season-ticket packages and consumers are given an opportunity to buy legitimate tickets in locations to which they typically would not have access. Ticketmaster has also run more than 400 ticket auctions in the first half of 2005.

But you can't say "auction" without eBay. The online behemoth has made secondary dealers out of anyone. "The brokers really were in their heyday in the late '90s, but eBay has come along and affected them pretty significantly," says Stephen Happel, an economist at Arizona State University.

So fear not. You might have to compromise on the dream of being at the edge of the stage.

But for a seat somewhere in the stadium for about the price of a great hotel room? Work the channels. You just might find, you get what you need.

• To determine if a licensed seller is a member of the National Association of Ticket Brokers, go to www.natb.org or call (630) 510-4594. You can also report counterfeit tickets to the NATB hotline.

Ten days ahead of a "sold out" Rolling Stones show might seem late to start a ticket quest. But that's when I got around to it, with rock-star nonchalance.

Listings on the Boston outpost of Craigslist.org, the online bazaar, pointed to desperation. A barker selling B2, row 8, couldn't resist all caps: MAKE ME AN OFFER; DON'T FORGET THESE SEATS COST ME $1,000 FACE VALUE. Not likely.

A better deal? It was just a click away.

Where I would land: Section 8-1AA, row G, seat 5, a sweet seat in the right-field box just a few rows above the Fenway turf - and with a front-three-quarter view of the towering stage across which Sir Mick would strut.

The price: $163, before the standard bundle of fees moved it close to $200. Not cheap, but face value. And risk-free, from a primary ticket vendor. (Yes, a solo seat is an easier find. One right in front of me would stay empty all night.)

The steer: a Craigslist post cautioning others not to buy from scalpers. The poster, a Red Sox fan, offered a link to NextTicketing.com - which handled seats not controlled by Ticketmaster. He'd received the link on a team e-mail promotion.

The window for my grab:small. The post vanished in hours. In an e-mail exchange, the Sox fan blamed scalpers for "flagging" his post to maintain their own advantage. (A handful of flags by other users can bump a posting. The idea: Weed out spam and deceptive advertising, though site founder Craig Newmark acknowledges there is room for abuse.)

The vagaries of the aftermarket can sometimes be avoided altogether. An Aug. 18 check of Ticketmaster found an upper-deck seat in the mid-$100s. A Sunday-night survey of neighboring seat-holders found that most had, in fact, acquired their tickets even closer to showtime.

One couple had bought newly released seats Sunday morning via Ticketmaster ($155 before fees). A Connecticut duo bought theirs on Sunday at $200 per ticket through a hotel concierge. A publishing CEO to my right allowed that he paid $400 above face value for his pair - as a donation to an early-literacy program.

Outside Fenway before the show, in an area often rife with scalpers holding thick rolls of bills and scoffing at face-value offers, most trading seemed more innocuous - if still unadvisable. Buyers of face-value "extras" are essentially in the clear legally in the eyes of the state, says Katie Ford, a spokeswoman for the Massachusetts Department of Public Safety. But doing so, she cautions, leaves a buyer with little recourse should the tickets turn out to be fakes.

For would-be buyers, it's often a judgment call based on an assessment of the seller.

Kathleen Cassetta bought her tickets on eBay three months ago for $163 each as a birthday surprise for her husband, Anthony. The seller had a four-ticket minimum, but guests of the Connecticut couple hadn't materialized. The Cassettas sought face value and were even willing to eat the fees. If the tickets didn't sell before the show, Mr. Cassetta said he would just stick them in his scrapbook. "We're young, we're in love," he said, with a sweep of his arm.

And going to see the Stones.