Why do we really use credit cards?

A new study found American credit card holders use their cards for convenience, rather than for rewards like frequent flier miles and cash back.

A new study from Bankrate.com reveals that 40 percent of Americans use credit cards for convenience, while others use their credit cards to buy big ticket items that they otherwise would not be able to buy.

In addition to making purchases more convenient, what else are Americans using their credit cards for each day?

"Credit cards were financing emergency expenses - that was 19 percent, and 14 percent were using them to earn rewards points and cash back," said Jeanine Skowronski, a credit card analyst from Bankrate.com.

The study also shows that most American card holders would not change their spending habits if rewards were eliminated.

"A large majority of consumers, 51 percent of them, would keep using their credit cards the same way if their issuer did away with their rewards programs," Skowronski said.

Although rewards points incentivize Americans to choose one credit card company over another, they are not enough to get Americans to share their personal information. The Bankrate.com survey also states that 72 percent of Americans are reluctant to share their information with outside parties in exchange for rewards.

"Given all of the data breaches, a lot of the stories that Americans have seen about the NSA, privacy is at the forefront of their minds," Skowronski said.

When choosing a credit card, Bankrate.com advises comparison shopping to find the most cost effective card for your lifestyle. One card is not best for everyone.

"It's really all figuring out what your spending habits are and then finding the best product that's on the market for you," Skowronski said.