Yeah, i think i need to explain this one, why other subdomain blogs can extremely earn than to those own purchased domain blogs in some sort of time, because i think subdomains blogs had a great alexa rankings already that most advertisers seek about on a certain blogs and of course subdomains blog gets a great stat around google because of the parent domain on it? thats how i look into it( not sure though) but i am not referring on the big bosses which the wordpress.com and blogger.com, ok i was telling to those online companies out there who can give a free subdomains blog using the wordpress as a blogging platform, yeah there was indeed a lot of that to the web, just search on them if you one to have one..because using the subdomains on wordpress.com is not appropriate due with some rules that you might to follow  under on wordpress restrictions though on blogger rather blospot.com you can rarely earn quite bit but still advertisers knew that the blogspot was owned by Google so they might cant consider your blog alexa rankings under the blogging platform..gets what i mean?

But on the other hand owning a self domain is a great one because nowadays broker companies are staring to require the new publisher/blogger to have their own domain to be ,so that they can get a lot of offers based to them, so yeah i think brokers are making a fair job to those people who spend some pennies and develop the site as much as the blogger can be..