Sometimes these bonuses are incredibly easy to earn: make one purchase, get $100.
More often, you have to jump through a few hoops to earn the bonus: spend $1,000 in your first three months as a cardholder, get $250.
The upside is that the bonuses that require extra effort to earn are often significantly larger.
The downside is that it's easy to make a mistake and not earn your bonus.
I've recently written an article based on my own experiences winning and losing with credit card sign-up bonuses. I've taken advantage of dozens of great offers over the last seven years, since I first became aware of these promotional offers.
To make sure you don't miss out on earning a credit card bonus you're working toward, follow the tips I've provided in my Bankaholic.com article, 9 Tips to Earn Your Credit Card Bonus.