I may go for Tier 3 or 4 plan, but couple pf questions:
a. 20,000 contacts is capped? or it gets renewed?
b. landing page and post landing page - how flexible are they in terms of designs, can i embed a HTML code here? also can I have 1 landing page for desktop and 1 for mobile - the embed link is of a youtube video embed. is the landing page easily customizable similar to Optimize page or leadpages?
c. I have 1 domain with which I want to connect SendFox, but there will be multiple landing pages - how do I connect to subscribers who opt in through different landing pages? The Sendfox feature - Lists and tagging to keep your contacts separated, can you explain this?