Every year when SIFF rolls around, casual moviegoers may pass the throng outside say, the Egyptian or Harvard Exit, and think, “There’s no way I could ever get a ticket to that screening–just look at the line!” The Seattle International Film Festival is, in some ways, a victim of its success. The largest popular fest in the U.S. (running May 21 to June 14), its hard-core SIFFgoers buy their passes months in advance. Volunteers keep the two lines–individual ticket buyers and pass-holders–neatly and strictly segregated, which makes each venue seem forbiddingly crowded.Add to that the changing ticket technology: Ten years ago, we bought tickets in person at one of SIFF’s several ticket offices; or we called to order by phone and credit card; some customers even resorted to the U.S. mail! Now, thanks to SIFF’s fancy Web site and coming iSIFF iPhone app, it would appear that you can cherry-pick your titles and buy your tickets the instant they’re available. (The box office opened yesterday.) You might think the poor, procrastinating, disorganized moviegoer might have no chance to score a ticket–especially close to a movie’s play date or on the actual day of show.But SIFF Managing Director Deborah Person says the opposite is true….”People aren’t planning as much in advance,” says Person. “Over the last five years, more people wait to day of show [to buy]. Our walk-up [traffic] is actually increasing.”SIFF, like other culture vendors, is moving away from the old season-by-season subscription model traditionally associated with the symphony. Why? “I think it’s the technology,” says Person. “We’ve made it so easy that people wait [to purchase].”The procrastinators and late ticket buyers tend to use the Web when the finally do make up their minds. According to Person, “Even day-of-show people buy online!” This reflects the overall shift in festival ticket sales to the Web: “Online is well over half, I would say 60 percent or so.”Of telephone sales–meaning voice to voice, not smartphone to Web–Person notes that “it’s been dying out.” Where SIFF once had eight people taking phone orders in festivals past, that number is down to two. “It’s really more of a help center,” says Person. (You can also still buy a ticket in person at any venue for that or another SIFF venue.)Despite the changes in technology, the absolute percentage of pass versus individual ticket buyers is about the same. “The early-bird sales make up about 20 percent of our sales. The formula has stayed about the same,” says Person. She estimates that “the average ticket buyer will see about two to six” titles at SIFF (this from a menu of some 400 movies). For that reason, she notes, “The lines don’t mean that the house is full. The odds are pretty good that you can wait. There’s almost always tickets available.”SIFF also employs a somewhat confusing set-aside formula based on the number of pass-holders who don’t show up in the short line. Add to that an allotment of “rush tickets” and, says Person, “We never say ‘sold out,’ because it’s almost always not sold out.”And, finally, SIFF’s Web site and SIFFter app will notify potential ticket buyers when those tickets are dwindling to scarcity. “Online, there is a little check mark” that will appear, according to Person. “It reaches a threshold at about 20 or so.” So that’s when maybe, finally, perhaps you should get around to making up your mind. Or just walk to theater, pretend the line doesn’t exist, and take your chances at the box office.