I am thinking for a mag of the month club. You get an email 7 days before the 1st of the month saying something like:
Dear Magpul Mag of the Month Member,
This months color is PINK.
mag will be charged to your account unless you would like to have additional mags shipped to you. Mags will be shipped on the 1st of the month.
You then reply and say "Please send me a total of 10 PINK
mags this month."
Maybe offer a special additional freebee order 5 or more get matching mag pulls one month, magpul logo sticker the next, Molle threading device, or Window for non-window price.
Order 10 or more and get a Bagman poster.