So your pins lead to a landing page then where you collect email addresses or to blogs with optins? Your write up on how to get started on Pinterest is great but as a reader I would want to know how 500K monthly views converts. ☺
On a side note, I run two Pinterest accounts. My newest one reached 1 million monthly views in under 6 months with decent traffic and conversions. How is yours converting?
Also while group boards are good, quality group boards are essential (25 is an awful lot!). I only belong to two but most of my repins come from tribes. Belonging to decent tribes is extremely effective.
So are you getting good traffic from Pinterest or organically?