Says on the site:-
"Why choose you?
Many other traffic services are scams. Your counter moves, but you never make a sale. They send visitors to tens or hundreds of sites, without the visitors ever actually seeing your site. We send real people to your websites, who will actually SEE your site."
However, it also says:-
"We use a mix of redirect traffic, full-screen popunders, and other full-browser-window sources to send visitors directly to your website affordably."
Any service that uses popunders to promote your homepage should be avoided imho. It can ruin your site's rep.
Google charges a min of $1 for every 20 click throughs. Or $50 per 1,000 impressions. You pay for what you get.