Web-banner ads are the digital equivalent of finding a flyer on your windscreen: unwanted and annoying.
What’s the point of pasting your banner-ad for tractors on a site for anime fans that gets 7 million hits a day (other than to tell your client the ad got 7 million views) when none of those views are going to convert into sales leads?
Wanna grab attention? Contribute to a blog. Write an article. Drive your tractors to a farm. In short: fish where the fish are. And use a net, not a spoon.