Here's the current offer that we received through our Disney Movie Rewards newsletter.
Choose 5 DVDs or Blu-Rays for $5, free shipping
1st Bonus disk $14.95, free shipping
2nd Bonus disk $9.95, free shipping
... sounds good so far!

5 more over 24 months, at a minimum of $29.95 plus shipping and processing
... hmm
Let's say you take the opening offer, and then take care of your obligation in one purchase, reducing the shipping costs, which is apparently $3.95 + $1.49 for each additional item. Further, we'll say that you do manage to pick 5 that are only $29.95 each. And let's say you're not paying taxes.
Total cost = $164.66 for 10 disks, or $16.47 each.
What if you take the two bonus disks?
Total cost = $189.56 for 12 disks, or $15.80 each.
Now what if you fulfil your obligation one disk at at time, and pay the $3.95 shipping on each? (And still take the bonus disks.)
Total cost = $199.40 for 12 disks, or $16.62 each.
There are bonuses available from time-to-time, where you get a disk for half price if you take the "featured" movie. These don't count towards your obligation, and since half-price is still at least $15 + $1.49 shipping, it doesn't really affect the math much, and in fact may increase your average movie cost. (So much for "Futher Savings!")
So for argument's sake, we can say that these disks are costing you $16 each. Financially, it's a marginal deal vs the average movie costs in local stores. What might swing it is the details of your movie choices.
Are there 10 or 12 movies in their catalog that you would buy today? If there are, could you get them cheaper elsewhere? (And, do they cost $29.95, or do they cost more?)
If you've got young kids, and don't own any Disney movies, this could be OK for you.
But we're Disney fans, and already own most of the Disney movies we want, so when I went through their online catalog and made my selections, I ended up picking 5 movies I wouldn't buy unless I had to.
So between that, and the math - DMC doesn't work for me.