When the bank hands you a hundred bucks for your new account, they plan on you sticking around long enough to make it worthwhile. In fact, the terms of your bonus probably say you must stay for a minimum period of time.
"If the bank is going to dole out cold, hard cash, they want to make sure they have some protection against the customer just taking the money and running," McBride says.
This protection typically comes in the form of a disclaimer stating your account must stay open for a minimum of six months. If it is closed, the bank deducts the bonus before you take your money elsewhere.
"Banking relationships take time before they become profitable," McBride says.
While the bank's profits increase during that time period, your profit from the initial checking-account bonuses slowly shrink as maintenance fees and ATM expenses add up.