Maker Box, Try Premium Filament CHEAP!

My partner and I started a company called Maker Box and we are shipping out our first boxes this month. I was wondering if I could get peoples thoughts on the idea and maybe some suggestions on how to improve.
Maker Box allows customers to try new filament without the overhead of purchasing a full spool. At just $20 a month, including free shipping to the united states, you will receive four different filaments at about 50 grams each in their own air sealed bag with a silica gel packet. We have partnered with manufacturers and resellers to allow our subscribers to later purchase full spools at a discounted price. We also do monthly give-aways that include anything from spools of filament to hot-ends and hopefully even 3D printers!
Please let me know your honest opinions and suggestions. If you would like to give it a try you can use the code MAKERBOX for 15% off your first purchase. http://makerbox.me/
Thanks!