Minneapolis (MN) - If you have a gift card from last year that's partially or completely unredeemed, you helped line retailers' pockets by over $3.5 billion.

According to the New York Times, an estimated $3.5 billion in gift cards went unclaimed during last year's holiday season alone.

Best Buy had one of the biggest pieces of the pie, with around $19 million in unused cards in 2007. Because its gift card operation center is based in Virginia, the unclaimed balances will go straight to Best Buy's bottom line.

Many retailers have done a similar set-up. Several states, including Minnesota where Best Buy is based, have laws that give the state government control over unclaimed gift cards (along with checking and saving account balances and the like). To bypass this, retailers set up standalone operations in other states that don't have these laws.