I am getting into the local coupon business. Appthemes "Clipper" Theme (http://www.appthemes.com/themes/clipper/) will be the coupon engine and there will be one (1) instance of WP 3.5.1 per county in New York (at least that's what I have planned).
The merchants will each link their coupon pages on Clipper to an iFrame page in their websites on the county db. (at least that's what I am thinking)
I have multi-site enabled and I need to know which configuration I should locate the two databases. One instance of WP, two db's. Subdomain? etc. I could use some advice.