Importance of Unique Visitors

I put away some money to advertise my business software, but now, after a couple of months of research and testing, I am convinced that at the moment I can spend thisbudget, at least not waste it. By now I think I’m an expert with respect to sites in Italydealing with management software and of course you can not enter in all my advertising because they are a direct competitor.
I did tests with the largest networks of PPC advertising (Pay Per Click), but the sites hosting banners are really low quality. Here’s what I’ve seen around the Internet, low-quality sites created by kids or almost can process only one topic in computer science: the reviews of software and hardware that is free of charge for the web or in magazines, various tricks and magic to see the film to release a latch or device.Actually there would be sites that have many unique visitors and are of great quality, but unfortunately they are of great newspapers, and I dare not even ask the price for a campaign. There are still too small to afford certain advertising budgets.
A few days ago I spent 10 euros for try a site that provided the PPI banner advertising(Pay Per Impressions), at first glance looked great because it was about business technology, but soon I changed my mind when I took 4 hits in 5000 impressions all from Japan or Korea.
If someone thinks you have a site on the Internet that has visitors suitable for my software, then he must know that I have a few hundred dollars to invest in advertising.