it's expedia.com. for e.g. when you cancel a flight, they wait a few minutes and call you at the number the flight was originally booked from. this is to make sure some joker doesn't cancel your flight without authority.

P.S. if picking up the phone to see who it is is such a hassle, then why do you go through the trouble of trying to call it back, getting upset, and writing on the net. quit being such wimps, and pick up the phone -- what are you scared of?
Caller ID: 2134570418
Caller: expedia.com
 Mar 13th, 2008
Okay. they have called AGAIN!!! this time for someone else. They won't leave a message.
I really am tired of these ppl.
 Dec 12th, 2007
This number ( hotel and travel agency)has called our business 7 times in 20 minutes. will not leave a voicemail for the person, keeps calling back over and over. Quite a rude lady, demanding I "put her thru" to that person, then when she gets voicemail, she calls right back. I advised her to please leave the person a message so the call can be returned, but she just hangs up and calls back instead.
 Dec 12th, 2007
Hotels.com calling me back because they needed more information
 Aug 03rd, 2007
I called Expedia about a hotel reservation. A few minutes later my phone rang back. This person said, "Ann" in a quiet, spooky voice and then hung up. Weird!
 Jul 13th, 2007
I received three calls from this number within 2 hours. Tried calling back--always busy.
 Jul 06th, 2007
I called Expedia and inquired about ther cancellation policy and as i was on another call rep called from this number and said whatever.
 Jul 05th, 2007
call came in rang once then hung up. I tried to call back the number but it was always busy.
 Jun 23rd, 2007
picked up the phone because i was waiting for a return call from a customer service agent and didn't know if it might be related. nothing but dead air on the other end.
 Apr 27th, 2007