Kevon Hills, vice president of research at customer analytics firm StellaService, said retailers' policies often come down to what type of merchandise they're selling.
For example, if a store sells highly seasonal products that would be out of style if returned a year later, it's more likely to tighten the time frame. Or, if the product is something that could be worn once and then returned — a problem known as "wardrobing" — retailers often enlist stricter standards to cut down on the risk of fraudulent returns.
For a similar reason, electronic items such as game consoles are often restricted to limited returns, Dworsky said. According to the National Retail Federation, retailers lost an estimated $3.8 billion to return fraud last holiday season.
The ability to make easy, free returns is especially important as more shopping takes place online. But an increase in returns also results in higher costs for retailers, particularly when they're done for free.