Probably ads for things that you would think of buying when you're standing near the fridge in the kitchen. So not Clash of Clans but La Croix.

Well, they probably won't be able to sell enough ad space to supermarkets, so people will get ads for "World of Tanks" and sports betting.

Contextual means based on related taxonomy of interest. How that interest is measured and what "related" means is proprietary.

This is distinct from demographic (trends based on physical attributes, like age) or geographic or behavioral (your buying patterns) and they already know the device targeting because it's their fridge.

Classic digital advertising vectors.

"I noticed you had Yoplait brand yogurt in your fridge. Here's a coupon for $0.75 off your first six-pack of Chobani!"

Don't some of these have "smart" features to detect what is actually in your fridge and tell you if you run out? I would think removing the last piece of butter could trigger an ad for whatever cow-milk-fat substitute won the highest bid on the brainfuck raffle that day would be shown to you.

Such a smart feature would most likely include reading labels, which means that the system would also know some of the medicines you consume. The fridge would most likely also record the user's interactions with the fridge, so the system will also know what your prescription amounts are. The possibilities of abuse are endless.

Another one: "you have consumed 20 units of alcohol this week, and run out. Should I order this 25 pack that is cheaper?"

Personalized ads are based on your user profile (ads for motorbikes because you're tagged as someone who loves motorbikes). Contextualized ads are based on where and when they're being displayed (ads for food delivery on the fridge late at night) but not on your user profile. This is the advertising industry, so they're probably lying, or they're not lying yet but they plan to add personalized ads later.

Ads for things it overheard you talking about recently.