I've bid many times, but only stayed twice.

1. NYC Marriott Marquis 4-star bid $125 (plus $25 bonus) for a mid-week stay just after Labor Day (first day of fall rate increases). GOOD

2. PHL Airport Sheraton. Bid $75 for a 3-star and was put at this former Days Inn and Four Points. OK property. Art Deco room interiors, but no new beds (i.e. leftover from Days). Sink o/s bathroom, antiquated air conditioning. Worse, AAA rate available for $75....foiled again! BAD

Still it's fun and I'll do it again.