Costco's famous samples are more than just courteous: studies have shown that they trigger an instinct of reciprocity and pressure to buy things at the store, as well as sparking cravings in customers. If you love samples, whether they make you buy more or not, here's the day of the week when you can expect the most variety.

Although weekdays at Costco are usually lighter-traffic days, meaning you'll be less likely to compete for a sample, variety in the samples themselves can be a touch scarce. For the greatest quantity and selection of samples, it’s best to shop on weekends, when more sample stands are scattered throughout the store.

In regards to timing, if you don't mind dealing with crowds and commotion, pop by Costco anytime between 1 p.m. and 2 p.m. as that's when most workers are out on the floor distributing goodies. This time frame works from Thursday through Sunday, since this hourly window is when most shoppers are present at the store.