A verb factory is a place or thing whose purpose is an act, not a product. That is, imagine a corn popping factory: sure, corn is the input and popcorn is the output, but the point of a corn popping factory would be the actual popping, not the before or after. (A popcorn factory, by contrast, would be concerned with the output of the process.)
One can imagine an infinite number of verb factories: the blowjob factory, where the input and the output are irrelevant, but the process is rather enjoyable; the school system, where the process of "education" trumps identity either before or after school; and so on. You could think of any verb factory as a sort of notional do-nothing machine on a grand scale.
For better or worse, most of the information economy is really a verb factory: with the possible exception of programming and other forms of content creation, mostly we just shuffle data around. Some of that data is money, but mostly it's just used to keep score. Marketing, sales, technical support, and the like are all economic verb factories.
It's important to note that the model here is essentially industrial, and that it's inappropriate to the way things should work. Verb factories aren't necessarily bad, but they often indicate that we're not looking at things as they are, only as we expect them to be. The factory model is appropriate when attempting to control input and output, but not when experience or process is the central thing.