I'm not kidding when I say that you would be surprised at the size of the market for canned air. I made this same joke several years ago and then looked into it and was blown away.
That typically isn't air (80% Nitrogen 20% Oxygen) but a liquefied compressed gas such as 1,1,1,2-tetrafluoroethane. They're very handy for cleaning things, especially computer heat sinks. Much more portable and cheaper than an air compressor.