No, that does not typically happen and advertisers know that. That is called direct response marketing (think coupons in your free weekly newspaper) and is basically the lowest form of advertising. Advertising is a broad field including much more common forms of advertising such as brand awareness where the goal is to make the consumer aware of the product so they will have it in mind when they make their next purchase. Also remarketing, which everyone hates on the internet, where the product follows you around trying to see if you'll buy it again. For traditional advertising this is all the catalogs you get in the mail for things that you have bought in the past. It's always odd that most internet ad discussions try to turn all marketing into direct response marketing.
It's hardly the lowest form of advertising. Direct response is massive. Think of any time you've searched for something you intended to purchase. Killer conversion rates. This is a way more tangible form of advertising than brand awareness, because the impact of those campaigns is immeasurable.
It's also a way more practical way to buy ads, because you know exactly what you're paying for and can measure your P&L in near realtime.
