Usually I am recommending that you have ads with strong calls to action for an offer (sign up for our webinar, download our market brief, get our infographic, etc). Those lead people to click, complete forms, give you their contact information, and enable you to further market to them.
However, you can use Google AdWords inexpensively to grow awareness by running display network ads that you pay for on a cost per click (CPC) basis that don’t have any calls to action at all.
Without a call to action few people will click on the ad. Since you only pay when people click on your ad, you can get tens of thousands (or many more) free impressions.
You can also use this strategy to move people from awareness to interest with remarketing.
True, you’re not going to get as many people to come to your website directly from the ads. You could do that in many other ways. This is just a way to inexpensively increase awareness.