There are a number of affiliate networks that specialize primarily in software affiliate programs. There are clear benefits to joining these: both for software brands and for affiliates who are interested in this niche. We recommend that you consider the following ones (which have traditionally focused on everything software, SaaS, and technology):
Although this article has been written in 2007, now in Feb 2014, I still find it full of great advice and tips. What I learned from this article is that when writing a review I should focus on how this product helped me achieve X instead of simply repeating and enforcing the features and benefits of the product that can also be found on the sales page.