If you are serious about making money. Get a domain and wordpress.org blog. It will only help you in the long run. If you get your blog going and then try and switch to a domain and wordpress, it'll be a headache.
Try
this post, maybe it'll help.
Also, with blogspot the money potential is there, but the intergration can be limited.
Read more about
affiliate programs at my blog here.
Keep posting/reading here, it'll be a great help.