I have already bought this service twice and will do so again but hell who does not like free so I will give it a whirl!!!
Backlinks are important for me (and anyone serious with SEO) as they are the backbone of SERP improvement. Say what you will about on page SEO and content and yes they are important but I have seen plenty of sites that have minimal unique content and "so so" on Page SEO yet they manage to rank on page 1, why? Backlinks.
Variety is key with backlinking A) it looks more natural- if there is a buzz about a celebrity, a game or a product where do we find the information? Everywhere!! Blog posts, forums, comments, articles and even press releases. So by getting those same types of links ourselves our backlinks tell the search engines that we have something fresh and newsworthy.
B) None of us know the algorithms that the SE's use, therefore the more variety we have in our backlinks the less damage we will feel if one of the search engines devalues a certain type of Link or if a certain number of links we have get devalued for other reasons.
There is my contribution, hopefully this is helpful to someone.