I work in advertising. More specifically, ad tech.

It's near enough impossible that you'll have never been influenced by an ad.

It's not that you think 'I need to go buy X product right now', it's generally the long tail of the funnel.

For example, your phone breaks and you decide you get a new one. You probably have a few phone brands in mind already, and that's because of advertising. If we pretend you've never heard of any brands at all, you might look online for what's a good phone within your budget. You'll probably find an article that's been written as if it's for the consumer but it's likely a paid ad.

You could come to Reddit, but a bunch of the recommendations will be paid ad accounts.

You decide to ask your mate 'John' who's very into technology what he suggests. Unless he's blindly bought each device and tested it, some of his opinion is going to be driven by adverts.

While you're doing all of that research, you'll have been put into an advertisers audience as somebody who's in the market for a phone, and the 'good' advertiser's will use that data effectively.

There's so many ad formats, some are more subtle than others.

If you go to a supermarket and they've got products on the end aisle with a discount out? That's advertising.

The companies who's ads you can recall being annoying are just running their strategies badly or you're not the target audience. The ones who knows what they're doing, they'll aim to deliver the ads to you just enough that it's in your subconscious but you don't consciously notice them.