For online shoppers, the flash sale is the ultimate guilty pleasure, and as many of us know (guilty as charged!), the promise of a limited-time bargain can be extremely alluring and even downright addicting. Instead of allowing your in-box to tempt you with unnecessary emails, we suggest you choose your memberships wisely. In this mom's guide to flash sales, you'll find the inside scoop on what's actually in-store at each of these kid-friendly sites. Limit your load (and your email in-box) and shop smarter. Your credit card will thank you!