Occasonally when I am online I will suddenly be redirected to a spyware removal site with no warning. Why?

I am redirected to this site

http://scan.spywaredestructor.com/scan.php?landid=2&depid=maxc%5Fclr08&cid=2271&parid=mc%5F3202928331

where it scans my computer and then pops up a download file popup when I have not asked to do any of this.
I have McAfee security and have scanned multiple times for a virus, but there is nothing. I dont understand why I am redirected to this site when I have never even been to this site.
Just a moment ago I was looking on ebay and suddenly after hitting the next page button I was redirected and it tried to force me to download their spyware destructor. Can someone please help me with why this is happening. I am very worried that something serious may be going on.

Some spyware programs redirect you to sites like that, but they are just trying to get your personal information through the site. Definitely DO NOT put any information into that site.

McAfee won’t catch all spyware problems, since it is primarily an anti-virus software. You specifically need a spyware program– google some and read the reviews to make sure it’s credible. If anyone gives you a link to one through this site, make sure you thoroughly check it out first.