Big grocery brands carefully plan the layouts of their stores, and it’s not usually about convenience for customers. Even if you’re perfectly prepared for a grocery shopping trip — you’re not hungry, you have a list, your coupons are clipped — one well-laid psychological trick can leave you with a higher bill than you planned at checkout. Even some more obvious sales strategies, like free samples, are deeper than they appear. Here are six ways that stores upsell you even on the quickest of grocery runs.

Listing sales price for multiple items

You’ve probably seen a sale tag that advertises multiple items at a certain price — like two cans of soup for $5 — but that doesn’t necessarily mean that you have to buy two to get the deal. Take a closer look, because chances are those cans are actually $2.50 each. It’s worth looking carefully at the tag just in case you do actually have to buy multiple things, but most of the time it’s just a technique to upsell you.

Displaying together items from different aisles

You’ve probably seen a sale tag that advertises multiple items at a certain price — like two cans of soup for $5 — but that doesn’t necessarily mean that you have to buy two to get the deal. Take a closer look, because chances are those cans are actually $2.50 each. It’s worth looking carefully at the tag just in case you do actually have to buy multiple things, but most of the time it’s just a technique to upsell you.

Displaying full-price items as though they were on sale

You’ve probably seen a sale tag that advertises multiple items at a certain price — like two cans of soup for $5 — but that doesn’t necessarily mean that you have to buy two to get the deal. Take a closer look, because chances are those cans are actually $2.50 each. It’s worth looking carefully at the tag just in case you do actually have to buy multiple things, but most of the time it’s just a technique to upsell you.

Stocking essentials in the back

One thing you might notice about shopping at a grocery store is that staples like eggs, cheese, and bread are rarely placed toward the front entrance — making you walk through a labyrinth of potential impulse purchases (and other sales techniques) on your way to your essentials. That makes it hard for even the most diligent list-makers to stay immune from heavy merchandising. Keep this in mind on your long journey to the back, especially if you can’t afford to buy extra snacks.

Displaying expensive items at eye level

Ever notice that store brands tend to be lower on the shelves than name brands? This makes the more expensive items easier to spot and more likely to end up in a shopping cart. There’s a very common exception to this rule: More expensive children’s cereals tend to be a little lower down, at eye level with smaller shoppers. Some are even designed so that the cartoon characters on the boxes are looking directly at the kids.

Free Samples

This one may seem obvious. Of course you’ll want to buy an item you try first if it’s delicious — and that’s a big part of it. Sales of an item can go up as much as 2,000% if customers get to sample it, partially because they know what they’re getting, but partially because they feel bad for getting something for free.

Yet the psychology goes deeper than just the product itself. After sampling something good, customers may be more likely to buy other things that they like throughout the store, not just the sampled product. In other words, while free samples can be great, just make sure to check your instincts after filling up on tiny bites.