Come up with a way to convince the people or companies that are featured on your blog to share your review of their company on their social profiles and maybe give them a short testimonial they can use on their site and sales or squeeze pages (preferably with a link to your blog, even if it's not clickable). It might be a bit hard to convince them to share your review but I trust you can come up with a way to encourage them to share it.
It would also be great if they can link to your blog to help improve your rankings in search engines.
You can also invest some cash and time on SEO, most hosting companies are not good with marketing, especially SEO so I believe you can outrank most of them with the right SEO approach. Implement some SEO, it even converts better in most cases.
Check out what other hosting review blogs are doing to get more traffic to see what's working well and replicate.
Another great technique is to have the best offers unlike other affiliates, that means asking the hosting companies to give you discount coupon codes or special discount links for your audience. That will make your selling much easier and enticing.
Hope that helps.