Last week, Delta upped its price by $10 roundtrip after joining in an earlier increase that raised prices as much as $50. But this latest increase didn’t last; Delta rolled it back over the weekend, and today United (the last hold-out) did the same. I guess we should be grateful for small favors. Other increases have “stuck” — keep reading for more on that, and what affect it’s having on demand from us passengers.

Here’s my latest update, or tally if you will, of the year’s increases (so far):

• 9 airfare increase attempts in 2008 - six “successful” (sticky)
• 5 increase attempts in the past 4-consecutive weeks - 4 “successful” (sticky)
• Many city pairs with over a $100 increase in 2008
• Increase Timeline (for 2008):

- January 3^rd, initiated by United, $10 roundtrip, successful (sticky)

- January 11^th, initiated by United, $30 roundtrip, unsuccessful

- January 17^th, initiated by American, $20 roundtrip, unsuccessful

- January 24^th, initiated by Continental, $20 roundtrip, successful (sticky)

- February 22^nd, initiated by United, $10 roundtrip, successful (sticky)

- February 28^th, initiated by Delta, $10 roundtrip, successful (sticky)

- March 7^th, initiated by United, $10 roundtrip, successful (sticky)

- March 14^th, initiated by United, $4-$50 roundtrip, successful (sticky)

- March 19^th, initiated by Delta, $10 roundtrip, unsuccessful

I am still surprised at how strong the demand for travel continues to be, especially since I’ve chatted with several people who expressed their concerns about this.

Northwest recently provided guidance on where its summer bookings were strong and others should be providing similar information in the coming weeks.

If demand stays strong — there is unfortunately no reason to prevent legacy airlines from continuing to attempt system wide price increases every few weeks for the foreseeable future.