Have never understood this one. Maybe it's just me, but could you help?
See, if I had to pay for it (the gift), it wouldn't be a gift in the first place, would it? And hence the 'free' is redundant. I know there are more such oxymorons out there, but this one somehow irks me a fair bit. One reason is, it's always visible - electronics stores that have sales! discounts! free gifts! Clothes that scream the same - buy one and get the other at half price. (And also a free gift.)
Which by the way, most of the time happens to be something entirely useless or even if it can be deemed useful (by a verrrrry long stretch of the imagination), it's not for me.
What, for example, will I do with a tiny plastic box that is non-food grade? Okay, so maybe it can be used to store say, um, play doh, or odd buttons or maybe a stray piece of jewellery. Hmm. But then for that, said box needs to be of a reasonable size! The play doh itself (in a single colour) can occupy a box three times the size. Hmph. As for jewellery, it's not me. On that, whenever I remind the significant other just how much he saves by not having to buy me serious jewellery/ trinkets, he just doesn't see it the way I do. Apparently, the books and wardrobe upgrades cost a small fortune. But I digress.
The other things I've gotten often enough at grocery stores are sachets of soup and ketchup. The soup will always be tomato (ugh), the ketchup some shady brand(?) that I'm not even sure is ketchup. Could be plain pumpkin paste with food colour for all I know.
The worst that I can remember is this one soap (I forget which) that offered a diamond pendant with some zillions of cakes. I mean, really! Diamonds? On soap? Who were they kidding? Paste stones, most likely. Am not sure any amount of soaps (that cost well under a dollar each) can stare confidently in the face of even the teeniest diamond.
Conclusion: There is no such thing as a free gift, and if someone promises you that there is, it's time to turn right round and head off in the opposite direction.