CashBackOffer

In 20 years of credit card use, I'd never paid an annual fee. It was a hard and fast rule, like paying my bills on time and never carrying a balance. But a month ago, I got an offer I couldn't refuse: 6% cash back on groceries, and 3% on gas. The catch: This upgrade would carry a $75 annual fee.

Have you ever shopped online through a "cash back" site? The main ones are ExtraBux, eBates, and Cashbaq. The way it works is you register for free at one of these sites, then click through to the retailer of your choice. They track what you purchase and send you a check a few weeks later with a...