We both ebay. We use PayPal and we have a credit card with a very low limit on it strictly for online shopping, so if anything happens, it won't be too bad. The card is completely paid off every month.
I buy things for the kitchen through ebay (I still love my Staub chicken roaster!

). DH buys some sports memorabilia from time to time. DH has also started to sell some of his overflowing stuff. And we've started to sell some of my aunt's things through ebay...so far, it's been working out well.
I also buy from Foster and Smith, Penny's, Amazon, Toscano, etc. I like to peruse some of the auction sites, too. We don't have a Sur la Table store close to us, so I shop online. I love Sur la Table.
I never really bought much online before. But several years ago, I had a bad case of sciatica and couldn't stand or walk for long periods of time. It was right around the holidays and I simply couldn't do a lot of shopping. I started shopping online and realized how easy it was. And the rest is history.
Since we both work, we usually have our items sent to my in-laws as they're always home during the day. My MIL will call me and I'll stop in to pick whatever it is up on my way home from work. That way, our purchases aren't sitting outside in full view all day long. (Sometimes our mailperson, who's a real sweetie, will put our packages on the basement steps at the side of house, where nobody can really see anything. Our regular UPS guy will do that, too.)