Kmuise mentions Wordpress here. There is a Free Word Press, and one that you have to pay for. You can download it, add plug ins, etc if you plan on spending hours, maybe months struggling with it.
The paid Wordpress requires a domain name and web hosting.
The problem with free blog sites is that most affiliate programs, etc give you your codes for everything in HTML.
The Free Wordpress limits what you can post on it such as affiliate links.
Word Press, the paid word press, users claim that Google loves it, and will rank it much quicker than it does its own blog sites (blogger) which comes up as a
Weebly gives you 2 free websites which you can change, delete and start over anytime you wish or as often as you wish. It has drop down boxes, including drop down HTML box whenever you need to use HTML code.
You can add as many pages as you want. For each page, you can add a blog as well, so you can have one or more blogs on one web site. The hosting is free for the 2 web sites.
There are a lot of free web site builders such as Weebly, WIX which many say is not great with Google because it is a flash site.
Most people have told me to at least have a paid domain name. I have one paid domain which is ranked by Google. All of my free blogs, by google, are not ranked and some are older than the blog with the paid domain. You do not have to pay for hosting if you have a paid domain name with blogger.
Blogs limit you in what you can do. Free web site builders may also require that you pay for a domain name, and/or hosting, which is the new gimmick. In other words, Free Web Site is beginning to mean Free Template only and you cannot use template unless you pay for a domain name and/or hosting through us.
If you are doing affiliate marketing, Free is the way to go. This way, you can test the waters, the market to see how well you do. But, as with anything it takes a long time to rank high in search engines, and to get a good PR with Google and other search engines. But, Free blogs, etc also allow you time and room to grow, to do some experimenting, tweeking etc.
Then, at the end of the day, Free Or Paid, if you do not have the traffic to your site or blog, your chances of making any money are ZERO.