Good question, Samantha. On this site we advocate being responsible when it comes to materials use and disposal. Unfortunately, almost all things take resources and create some amount of waste. Magazines are often produced with pulp from renewable tree farms, and can be easily recycled. So if disposed of properly, magazines can be a relatively low-impact product.

I've suggested several ways several times for the rewards to be more environmentally friendly. Work with a national thrift store chain (Salvation Army for example) or used book store to provide gift certificates. Offer coupons for things like garden seeds and canning supplies. The only thing I've found worthwhile to redeem for are the magazines because I pass them on when I'm done and once in a great while find some useful information in them but I'd much rather prefer things that would be more useful.