Welcome to the forums, elinera!
Anybody who doesn't want their card can send it to me! I like money, tangible cash or intangible balances on cards, it don't make me no never mind! So y'all all can send 'em right over to me. Happy to oblige!
I have to agree that these are frustrating. The biggest issue I have with the cards is the expiration date tends to be rather short. My solution (may not appeal to all) is to buy Amazon gift certificates for myself. Once I apply these to my Amazon account they never expire and I clear out the total amount on the card. Personally this works for me as I tend to buy enough from Amazon and that GC balance does not last that long in the account.
A couple of notes when doing this through Amazon. If you try and buy a larger gift certificate, they will check the validity of the card by hitting it with a temporary authorization for $1 which will then make it impossible to get a GC for the entire amount of the card. There are two solutions for this. One is to only purchase $5 GCs and buy enough to use up the entire balance. They will not do the $1 temporary hold for $5 GCs. The other option which take a bit more time is to purchase a GC which is $5 less than the balance on the card. Then you will need to wait for the hold to clear to use the last $5 on the card. Amazon has a minimum of $5. Also, I am making the assumption that you are using email GC which has no shipping charge.
I get more and more of these "rebate" cards which I can only guess is a benefit to the company giving these. Apparently a lot of them never get used while the older check method was usually cashed. I know AT&T was hit for the short expiration of their cards and had to send out compensation cards to some customers (I was one).