A big question as the Blender Market grows is what will be the most popular type of product? I've had a hunch since the beginning that the most popular category of products, based on the number of sales, would be add-ons. So far this is proving to be true. As it stands right now, add-ons account for around 6% of the total products but they make up approximately 64% of all sales. This is quite significant. I believe there's a good reason for this too. Add-ons, perhaps more than any other product, are basically tool upgrades. They allow us to do more with Blender, and often do it more easily and faster. Add-ons also have a long lifespan. A single add-on may stay in your workflow for months or years, while a model might get used once for a specific project.
This bodes very well for all of the add-on developers out there who want to help build a repository of professional, supported add-ons for Blender.