The Internet Runs on Ads, let's use them to our advantage.

First, let's start by defining what is an advert.

"Advertising is the practice and techniques employed to bring attention to a product or service. Advertising aims to put a product or service in the spotlight in hopes of drawing it attention from consumers. It is typically used to promote a specific good or service, but there are wide range of uses, the most common being the commercial advertisement." -Wikipedia

Picture a giant billboard, that instead of showing ads for products that you are not interested in, portrays on that exactly matches what you are looking for at this instant. Generally and historically, these billboards will try to display a product or a service to appeal to the masses. Some people will relate and find themselves in what is reflected. Others will sill stumble on the billboard and will still take time out of their day to scan and reflect about an advert that does not meet their needs.

It would definitely help some people out, but how great would it be if it changed to match exactly what you are looking for today and furthermore, changes to each new person taht comes by.

There's another dimension to this. If you don't know a product or service exists, you won't engage with it. For example video-game enthusiasts are more likely to keep track of games releases. However the mainstream audience will know of a game from the marketing and advertisements, and will only get exposed by external factors, not their own desire to know. These people will still make a portion of the sales or that product overall.