I have been a blogger for over 10 years- worked with quite a few affiliate networks and I have found that shareasale has been the best overall. I have used their platform and prefer it over others for almost all of my links and programs I am signed up with.
Their platform recently got an update and it's been a wonderful change. Easy to find new companies to promote, easy to customize links for better tracking and they have been there to answer any questions that I might have.
I also have been a merchant in their network for over a year and that has been a great experience as well. As it takes time and work to run an affiliate program and get it running smoothly (not on the part of shareasale- just running the program in general) there are many resources for sending newsletters to affiliates, tracking reports and updating databases. Again, any questions have been answered and many hours spent on issues that I may have to get them resolved.
While it is the responsibility of the affiliate and merchant to use the program and generate their own income based on their efforts- shareasale provides training and helpful articles to better understand affiliate marketing, increase clicks, income and conversions. I have found these very helpful as the internet world changes often and keeping up on everything can become confusing and time consuming.