There is tremendous competition for the consumer's attention these days. Any opportunity to grab his or her awareness--even for a moment--is precious. The other day, I noticed that advertising has now crept onto the fold-down trays on U.S. Airlines' seats. On busy flights, the crew will sometimes ask passengers to have their trays opened before the beverage station reaches the the passenger, prolonging the exposure to the advertising message. Hopefully, with clear plastic glasses, the beverage will not cover the advertising message.
This is one of the more devious tactics I have seen recently. It will be interesting to see if passengers--used to nice, neat, clean trays--will object to what may seem like aesthetic revulsion.