You have selected the Level 2 membership level.
In addition to getting free posts by email, you get to comment on ALL posts - not just the free ones. You get full access to Members Only posts, 1 week early access to special comics, and access to process/research/BTS posts. Plus if you're on Instagram, I'll add you to my Close Friends list so you can see more process/research/BTS goodness.
Also, if you feel this is worth more than $5 a month, you have the option of donating more.