Why these pop-ups?

I'm hoping someone can help me out here cause these pop-ups got me nuts! I use Safari 6 and since I first saw pop-ups I installed the extension called Adblock but I still get pop-ups. I don't get the ordinary type pop-ups you would expect but pop-ups come when I see a link or a highlighted name and when I point to it I get directed to a place that is wanting to sell me something.Has anyone ever seen or heard of that? Its so weird and very annoying! If anyone knows how I can rid myself of it please help. Thank you.

Thanks for your help and I have another, the problem I'm having is when I first boot-up I have no sound but if I plug my headphone plug into the jack in the back of my mac, the sound comes back. I don't get it??? Whats wrong that I have to keep pluggin' into my Headphone plug on the back of my imac to make the sound turn on? I've never heard of such a thing? Someone Please tell me why this keeps happening???