Can Anyone Explain These Sites?

I’m getting clicks from these sites and I am wondering what they are and If I need to block them in the Yahoo search (if that’s where they are coming from) I’m guessing they’re not a good thing for me unless I’m doing what they’re doing, so can someone explain ? Here are a couple of sites:
http://searchnut.com/
http://www.mapestoys.com/
http://www.conversiontrac.com/

Thanks
gary

Original post by GaryD