Hello there,
Please read these support entries so you are clear on the situation:
1. Free hosted WordPress.com blogs cannot be used to drive traffic to third party sites (section 2 – 5th bullet) http://en.wordpress.com/tos/
2. Types of blogs – what content is welcome and is not welcome on WordPress.com > http://wordpress.com/types-of-blogs/
scroll to this section and note how limited it is:
Affiliate marketing blogs: Blogs with the primary purpose of driving traffic to affiliate programs and get-rich-quick schemes (“Make six figures from home!!”, “20 easy steps to top profits!!”, etc). This includes multi-level marketing (MLM) blogs and pyramid schemes. To be clear, people writing their own original book, movie or game reviews and linking them to Amazon, or people linking to their own products on Etsy do NOT fall into this category.
3. No blogger initiated advertising of any kind and most particularity of any if the get rich quick schemes is allowed on free hosted WordPress.com blogs > http://en.support.wordpress.com/advertising/
Note: To support the service (and keep free features free), we also sometimes run advertisements. http://en.blog.wordpress.com/2008/09/18/go-ad-free/ We’ve tested a lot of different ad providers and currently use Google AdSense and Skimlinks. We try hard to make the ads discreet and effective and only run them in limited places. If you would like to completely eliminate ads from appearing on your blog, we offer the No-Ads Upgrade. http://support.wordpress.com/no-ads/
4. If a blog has been found to be in breach of the WordPress.com Terms of Service, it will be suspended. http://en.support.wordpress.com/suspended-blogs/
Additional reference > http://support.wordpress.com/com-vs-org/
Hope this helps. :)