They make it look like you're getting a lot more than you really are. It's a 'sneaky' trick.
It's a 'sneaky' way of getting people to buy something they don't need.
a 'sneaky', untrustworthy person
(..) I knew how this would be settled in the animal world. But this was Girl World. Your hair looks sexy pushed back. And in Girl World, all the figthing had to be sneaky. All this cranberry juice is making me break out. Wait. I have this really good skin stuff I'll bring you. OK. (..)2004 Mean Girls
(..) If you know what's good for you Tighten. You'll stay out of Montrosity. - You got it! - Good! Pretty sneaky, sis. But there is only one person I know who calls this town, Montrosity. Ooops. You! Bet you think it's really funny, huh? (..)2010 Megamind
(..) You will make the soup again, and this time, I'll be paying attention. Very close attention. They think you might be a cook. But you know what I think, Linguini? I think you are a sneaky, overreaching little... Rat! - Rat! Get the rat. Linguini. Get something to trap it. (..)2007 Ratatouille