Originally Posted by
cjt105
Hmmm, interesting. I've always assumed that some of these sites temporarily "hold" seats, and hence if you're comparing around, you may end up holding all of the seats available at a particular point.

Now that is certainly possible.
I think I've even seen Opodo populate the full PNR, including my BAEC number (I'd gone reasonably far in the process, but hadn't confirmed it or done card details yet).
Then I made the booking elsewhere where I was getting a better price (lower card fees, etc).
Went to look at BA.com to pull up my booking, and was rather alarmed to see myself there twice. The opodo unconfirmed one disappeared within a few hours.