As with any purchase, know your product. I purchase a lot of things online, but I usually have researched the item before. Also, only purchase a using PayPal. That way if you have a problem, they may be able to assist you. If you don't use PayPal for purchases, I suggest to people that they get a small limit credit card from their bank and use it for all online purchases or bill paying. It is simple enough to transfer funds into this account (on bill paying day or before a larger purchase) and this protects you from someone taking this number and misusing it. Unfortunately, in today's world you should be careful about where you credit card numbers are floating around!