Shopify has three different account types as well as standalone third-party products like themes and apps. Commissions are paid for sales of any of these products, including users who sign up for a 14-day free trial and then convert to a paid account. Shopify also has a wide range of blog posts, webinars, and video tutorials that can be linked to with the standard commission paid on any sales that are generated.
Wealthy Affiliate is also very strict on spam, which in the end is a GOOD thing, but I have to be careful sometimes about promoting my sites or referencing them. Sometimes I do have valuable information on my site that I think could help people during live chat sessions or Q&A’s, but I don’t share because I don’t want it to look like I’m spamming. They do allow people to promote their sites in certain areas, but in order to keep the community from filling up with self-promotion spam, there are times when it is best not to share certain information from outside sources, especially my own sites.