[briansmith]

Tripeedo has two obvious advantages over Kayak:

(1) It can help you search discount airlines like JetBlue and Southwest.

(2) It will show you fairs that are exclusive to the airlines' websites. (I don't think I've ever run into a situation where the airline's website had a price significantly lower than what was on Kayak but I've heard rumblings that it happens.)

[jpwagner]

I agree with both of these thoughts, but where is tripeedo when kayak partners with all of these?

i recently went to hong kong and searched all of these engines and got discouraging prices. I did one search on Cathay Pacific's website and saved close to 40%. I'm almost positive you won't see this with domestic flights (for now.)

[potatolicious]

They won't partner I don't think. Airlines dislike fare competition, it drives profits down and worsens their already-bad financial situation. From the couple guys I know who work in that industry, there is real push-back against aggregation sites.

You also provided the evidence of this yourself - I too have had a lot of trouble with Kayak recently, and it seems their ability to scrape accurate fares is severely compromised, and I suspect that airlines have some hand in this.