If there's one thing that people know about me, it's that I love free stuff. I posted about Ebates a while back and have continued to use them as my main cash back location of choice, but something else to consider is branching out a bit. The past few months, I've expanded my options based on store availability, percentage of cash back, and other options and I've been handsomely rewarded as a result. Here's how I would structure my online shopping:
Ebates. I still consider them the granddaddy of the online kickback revolution, and I still use them the most. They either deposit money in your PayPal account or send you a check every 3 months. They seem to have the largest breadth of stores, and they give you that swank signup and referral bonus. In a year and a half of actively using them, I've gotten $1475.
Fat Wallet. These guys have a better selection in some areas (notably eBay and hotels), and since I book travel here at my company as one of those vestiges that I hang on to from other positions I held, that's a big deal. I started with Fat Wallet four months ago and have got $300 in cash back from them during this time. They send you the money via deposit in your PayPal account 90 days after any given transaction.
Live Cashback. This is Microsoft's entry, and as such they have deeper pockets than the other two. Microsoft was running a deal a while back where they'd give you upwards of 30% cash back for eBay purchases, enabling me to get a 60 GB PlayStation 3 for my Blu Ray player of choice for a fraction of the original cost. They get into some places that the other sites don't, and for the overlaps, they pay a little better. They also deposit the money in your PayPal account after 90 days, similar to Fat Wallet. I've gotten $240 in the two months since I started using them.
When you combine these, especially if you happen to purchase things for your company, you can get a pretty sweet little folding money stream coming in.