One of the classic commercials of the 1970s came from V8 (they have updated ones as well!). Unknowing consumers of snacks and sodas realize mid bite/drink that they could have had a V8 instead of their other choice. The concept of opportunity costs is that by consuming an item, you give up the opportunity to consumer something else. A rational individual will pick the item with the highest level of utility, but sometimes we aren’t fully aware of all the alternatives. The individuals in this commercial only realize when it’s too late.
The clip was described in Joel Waldfogel’s book, Scroogenomics: Why you shouldn’t buy presents for the holidays. Dr. Waldfogel also appears in an Adam Ruin’s Everything episode on the inefficiencies of gift giving.