explorador - 3:55 pm on Dec 3, 2009 (gmt 0)

I've hired someone to do some link building

That sounds good

This guy has created a blog on BlogSpot and writes an article a day related to our topic

Added to the previous point, it doesn't sounds good anymore

Call me paranoid but he is building a source of traffic (and then bringing visitors to your site) but the thing is, he has the source, he is building something that is not yours and you have no ownership.

In other words I think you might be paying the guy to build something he might use anytime for something else, even to put Adsense on it. Just my opinion.