Are airlines withholding seats so you'll pay a premium?

— -- A few months ago I booked a flight for two and then went to select seats on the airline's site. Based on the destination and time of year, I was surprised to find only two adjacent seats were available without paying a premium. But I was even more surprised a few weeks later, when we boarded the aircraft and a flight attendant announced that only 30% of seats were occupied, so we should all feel free to stretch out.

So how could a flight that looked nearly full a month earlier wind up with seven out of ten seats empty? That's a question only the airlines can answer, and they're not eager to provide many details.

Are some carriers intentionally holding back seat assignments, in the hope we'll all pay for "premium" seats? It's a fair question, and the evidence is intriguing.

Behind the screen indeed

An awful lot goes on behind airline and travel booking screens, and much of it is strictly off-limits to consumers. What we do know is that for decades now airlines have become masters of what the industry calls yield management, offering millions of combinations of fares based on advance purchase patterns and other booking trends, so nearly everyone pays a different price based on when they buy. But now that paying extra for your seat selection has become common practice, securing your reservation is just half the battle.

Some industry experts have connected the dots. "They're trying to get people to buy premium seats," says George Hobica, USATODAY.com's Fly Guy columnist and the founder of Airfarewatchdog.com. "They want to increase revenue. And we're getting more complaints about it." He notes that it "really annoys" passengers who want to sit together, particularly when traveling with small children.

He's echoed by Kevin Mitchell, chairman of the Business Travel Coalition: "With yield management, consumers are aware and they know that airlines are constantly changing prices on seats. But if this is true, it is unethical—they're grossly misleading us. The thing that I find so offensive is conveying to me that I have no options, but if I wait a week or two then I do have options."

According to the airlines, the raison d'être for ancillary revenue is unbundling ticket prices, so passengers who desire a given service—say checking a bag or ordering a soft drink—pay for it, while those who don't are spared the cost. But as Mitchell notes, "There's another twist to this. The airlines are saying fees are for 'optional services.' Well, seats aren't optional!"

Of course, securing a good seat isn't an issue if you're in first class or you're an elite member of a frequent flyer program. But what about the rest of us? As I've pointed out repeatedly in recent columns, we're faced with record-high load factors, the highest for the U.S. airline industry since World War II. But even with the average percentage of occupied seats for domestic flights at 82.7%, it's still an average—some flights will be fuller but others will not, particularly weeks in advance. Yet searching for seats keeps getting harder and harder.

Seats for sale