I assume this is a nationwide offer - as advertised heavily behind the food service counter at the Tamworth Odeon. When you buy a filmfeast for £2.95 (available at evenings too - bag includes popcorn, packet of sweets and a small soft drink of your choice), each pack contains a 2 for 1 voucher for use on a Saturday or Sunday morning until the end of July.
I bought the filmfeast when I saw Sex and the City a few weeks ago, and the kids and I went to see Enchanted for £2.50 last Sunday! These are cheap sessions anyway so I was pleased to get in even cheaper!!
Might be worth checking if there are any kids club films you would like to see between now and the end of July first though.
As adults go free at the film club I would of thought 2 adults could be admitted with two kids for the £2.50 too, but we didn't try this on this occasion.