If the Quest $100 deal is the same one I checked out yesterday, they also offer to take your name off of telemarketing lists. This is automatic and includes MCI, SPRINT and ATT so you will never get another offer to "comeback".

I called that 800 number for 6.9 cents, they gave me an access number to use during the day, so it did not switch my carrier (10-10-XXX). I also got the 800 number for only 6.9 cents a minute, no monthly fee. haven't been able to beat that one yet.