Visited local Early Learning Centre (Lancaster) and they had large rack of "Sample" copies of a new, childrens Something Special comic (1st issue out 6th April)
Kids immediately spotted them and was surprised that they were FREE. 16 pages of activities and stickers, plus 50p off voucher that can be used for one of the first 4 full issues.
No limit to number you could pick up, as they were at the front door, but I let my kids take one each.
Not sure if store specific, but worth a visit if you've got kids that like this sort of thing.