Hand waving Flags are the most effective when you have the opportunity of distributing them to a crowd, people who are happy or excited or both, and are having serious temptation of raising their hands and waving them to stymie the progress of the infective enthusiasm and channel it out by vigorously activating their hands as energy dissipators.
Well, no seriously, give those hands something to wave, they'll volunteer, give them for example, the team logo on one side and your advertisement on the other, if its a game of football or cricket ( do not try in Test Cricket, they only clap in England ) and in case of a concert, put the rockstar on one side and your brand on the other, you'll get those hands waving them all night. Waving means what? seeing, yes other people seeing your brand in thousand hands. Isn't that a good idea!
Coming back to the subject, yes these flags, these bespoke hand waving flags are effective in other scenario too, in fact anywhere a bunting flag works, a hand waving flag works too, places where people make a crowd to celebrate, flags work very well there.
Everyone knows stock hand waving flags are loved, for that matter anybody who is man enough loves his football team till death, and a pennant with his team logo on it is as good as the Excalibur in King Arthur's hand, you can't separate a faithful hand from a team hand waving flag. So for teams this is a wonderful tool for advertising and arousing brotherhood and loyalty, but only stock options do not always work, you need to get updated flags, evoking emotions related to the current event, with slogans that are enough to peak adrinalin, and this is where custom or bespoke hand waving flags are required.