"Magic diet pill," "lose ten pounds in a week" and "scientific breakthrough." These messages may sound tempting, but don’t fall for them. Weight-loss products are the No. 1 scam consumers fall for. Over 5 million Americans bought a weight-loss product that didn’t help them.

At least 2.4 million Americans paid money, made a purchase or attended sales presentations for promised prizes but never received any. Prize promotions are Marketlace Money's No. 2 fraud US consumers fall for.

Another popular scam is work-at-home programs, where 1.8 million consumers paid for work-at-home programs, but they didn’t even earn half of what they were promised. Working at home is a tempting offer, but watch out for ones that require money up front. Also be wary of payment processing, envelope stuffing, and e-mail processing jobs. You’ll spend hours working and never meet your quota.

Another popular fraud people fall for is credit repair scams. 1.7 million Americans paid someone who promised to help remove negative information from their credit report and it turned out to be a scam. To play it safe, always do your own research.