Taking advantage simply requires creating an account and forking over the $50 to purchase the deal. This gets you a code that you can use to redeem for $100+ of merchandise at VibramFiveFingers.com. What more, all orders in the U.S. and Canada through December 2012 get free shipping.
Note: code-driven orders off VibramFiveFingers.com in 2013 will see normal shipping rates applied and your code will expire February 5, 2013. Also, you can't stack coupons. So you can't, for example, buy a pair of Lontras ($150) plus 4 pairs of Injini Crew socks ($12/each) for $100 via two codes. However, you can buy multiple codes for separate orders.
Best deals? Anything that tallies up to $100. SeeYa LS MSRPs at $100; so you get them for $50. Same goes for the SeeYa which is $100 regularly. KomodoSport LS is $110, so they'll set you back $60 with this deal ($50 off). The Speed XC is $140 so you save $50 and get them for $90 ($50 coupon + $40 over hundred). Make sense?
One more thing! The Shoe Mart has a number of Vibrams on sale at closeout prices (e.g. Bikilas for $50; KomodoSports for $55; Speeds for $70). Well, if you go there and use coupon code Birthday5, you'll get an extra $5 off your order. That applies to sale and non-sale items (and works for now ...). The Shoe Mart offers no minimum free shipping on domestic U.S. orders; and while they do ship some shoes internationally (Merrells and New Balance), they don't ship Vibrams internationally or free.