My friend recently signed up with Qwest for her long distance service and received a $50 bonus for signing up. In addition to bad service (scratchy, hollow), when she tried to switch, she was told by Qwest they would be billing her for the $50 dollars, saying she had to stay 6 months or the offer drops. Didn't bother to mention this to her when she was cashing the check.
Apparently this is a hoax set-up to tie you in financially to a 'contract' so you can't switch without penalizing you for money you probably already spent.
I have one other friend who recently switched to Qwest communications, which offered her a $50 dollar check to switch to Qwest. Aside from having horrible line service (scratchy, hollow), when she decided she wanted to switch, Qwest informed her that they would be taking the $50 back! The $50 is apparently some kind of Indian gift designed to make you stay around 6 months because you probably spent the $50 before you realize there are strings attached.