Where to pay for ads for my software?

That isn't a search engine. Anyone had luck with Softonic or Download.com ads? Any good way to pay for quality traffic for my application? It's a tool for Windows system administrators.
Thank you.

Search engines are good since that where the vast majority of people go to first when they are searching for something. So why not use take advantage? I would use Google Adwords and Bing.

But maybe you have the type of product that people don't think of looking for. You should then have an awareness campaign. Surely there are blogs and forums catering to your demographic. Many of those sites monetize with ads, particularly Adwords.

I haven't created any new software in the last decade suitable for a large audience that could be uploaded on sites like Softonic. But they are a good place to get visibility.