Wait a second. I know its a fine line, but there are great tips on deals shared here all the time. And many people appreciate the savings. So I wouldn't quite go so far as to call it spam...
its been around for a VERY long time from what i have researched. people on various other forums have been using this for months. the percentage off varies from week to week or even between days. the range has been 10-30% off. right now is the highest its ever been