NEW YORK -- At 7:48 p.m., 15 minutes before Jennifer Capriati's U.S. Open match was to begin Tuesday night, 25-year-old Brooklynite Joe Serure and his friend David, were escorted to some very expensive club seats, just four rows behind the baseline on the north side of Arthur Ashe Stadium.

The usher wiped off the seats and the two sat down. David pulled out his wallet and handed $20 to the usher, who pocketed the large tip and went back to checking tickets.

Why did a 20-spot change hands here? It wasn't the usher's great ability to find the right seats, nor the fact that he cleaned them particularly well. The real seats Serure purchased were some 50 rows higher in the upper promenade. Their price? About $300 cheaper per seat.

"Last time I paid an usher, I was sitting three seats away from Spike Lee and (Saturday Night Live's) Tina Fey and Liev Schreiber was a couple seats away from them," said Serure, with a large smile on his face.

Serure was not the only one who paid his way into the up-close seats minutes before the Capriati match. By the time play started, the same usher -- who wouldn't comment on his actions -- had facilitated four visible transactions in the 128-seat area that was under his control.

The U.S. Open is not immune from the good ol' seat upgrade. On any given night, a keen observer can watch many deals being done.

Although getting close with a nosebleed ticket could easily cost the patron the price of another bad ticket, the money saved can be astronomical.

"Last year, I gave this same guy $300 on the first night," said Serure, a real estate broker and a New York Knicks season ticket holder. "I bought the cheapest seats each night and that payment got me through the first five or six nights."

Serure says he saves about $600 a night during the first week by buying cheap seats and negotiating once inside the stadium, rather than buying the hard-to-get tickets from a broker.

As the matches gain importance, the price for a ticket rises -- and, usually, so does the usher's asking fee. Officials with corporations that buy the club seats are also more likely to show up in the second week, leaving the usher fewer seats to work with.

While fans might strike out with a couple of ushers, a passionate fan who insists on an up-close view for a fraction of the price is bound to find a taker, who risks his or her job with every transaction.

"Our ushers are under constant scrutiny," said a spokesman for the United States Tennis Association. "We do not tolerate this behavior and anyone accepting money for seat upgrades will be relieved of his or her duties immediately."

"If the government can't make money on something, they say it's illegal," said one usher, who asked not to be identified since the USTA does not allow ushers to talk to the press. "It's the same thing here."

While there's an inconvenience in having a ticket-bearing customer wait as an usher moves the patrons who paid him or her, the seat upgrade isn't taking any money away from the USTA because the seats are already all sold out.

The workings of the system are not hard to document after only a half-hour of observation.

The largest exchanges of money happen before each of the night matches at Arthur Ashe Stadium. Some ushers insist that all business is taken care of out of the way before the fan sits down. Others, like Serure's usher, didn't care that the deal was being done in front of anyone who was paying attention -- certainly a risk as a roaming supervisor can see from afar the usher's number, which is embroidered on his or her hat.

The ushers roaming the club seat area appear to be older than those in charge of the higher-up seats.

Seniority is a valuable virtue, considering the loot that could be pocketed by a cunning usher in the club seat area. Up above, ushers don't usually earn more than the hourly rate and -- unlike some of their compatriots -- they're reporting all of it to Uncle Sam.

As the usher does business, he or she keeps track of where the paying patrons are and spreads them out to reduce the chance of having to move more than two customers at the same time. If a section fills up with ticket holders -- which it usually does not the first couple of nights -- the usher might have to work with another usher and move the upgradee to another section. After this happened once on Tuesday night, the two ushers could be seen talking to each other, but the second usher didn't appear to get a piece of the pie.

An usher who wants to cash in has to keep active. The usher who gave Joe and David their seats protected his territory well. Three teenagers tried to sneak into seats right before the Andy Roddick match was to start later in the evening and he directed them out, perhaps knowing that each seat taken without his knowledge was squeezing his potential revenue stream.

While Serure doesn't like the hassle of sometimes moving seats in mid-match, he understands it's part of the discount.

"If I really want to make sure I see someone, I'll pay a couple hundred dollars for these seats," Serure said. "But if I'm just here to see some good tennis, there's no reason not to go through an usher."

Darren Rovell, who covers sports business for ESPN.com, can be reached at darren.rovell@espnpub.com.