The TMM Insiders group is a blogging membership group I pay to be a part of. TMMI aggregates the purchasing power of a bunch of bloggers and gets a lot of the critical services for us at a lower cost.
Spencer and his blog Buildaprener are all about affiliate marketing. Not only does it teach AF, but it also teaches marketing techniques you can employ for your own digital products=, coaching, or consutling.
Michelle runs a highly successful blog about personal finance. She's a fantastic blogger with a huge audience. She was also very gracious in allowing me to guest post on her very popular site.
Glenn is another SEO sensei. I decided to find a second SEO course to buy, just to make sure I was getting a good swath of info. While Glenn and Brandon cover a lot of the same ground, Glen has his own secret sauce.