Costco's Executive membership gives you 2% cash back on purchases. But there are rules for where you can spend that money. Read on to learn more.

Costco offers two tiers of membership to choose from. You could pay $65 a year for a basic Gold Star membership, or upgrade to an Executive membership for $130 a year. The Executive membership gives you the benefit of 2% cash back on your purchases in exchange for the higher price.

Have you heard of Costco's other members-only website? If you haven't, well, you have now. Here's what it's all about and how you can shop there.

Here are a few of the ways you can make a Costco membership work well for your household of two. Costco naturally works well for a household with two adults, as you can have two cards per membership, so long as the other person shares your address. This means you and your spouse or roommate can each get your own card.