Blogs are going to be increasingly hard to pull in traffic. Pretty much everyone has one nowadays. You'll need either brilliant content or an already-existing huge site.
Blog are great to get traffic, and the best advertising for them is word of mouth. If your blog is interestng, you will have traffic and sales. The most difficult with blogs is to update them regularily with good content.
I dont see the point of using copied material. Many people will do this and not leave a link. I have this happen to me all the time and so do many others. In most cases the sites are just a bunch of copied articles and perhaps a little bit of there own content. The sites are never more then pr 0 and never have many links pointing back to them.