It's also likely that someone who wants to enter $FIELD_OF_STUDY might use one of these as a portfolio piece. You learn-and-implement one of these algorithms to get an introduction to the field, you get a bullet point for your resume and you make a few bucks.
"Royalty
Algorithm developers may choose to set a cost-per-call royalty associated with their algorithm"
This is a fantastic race to the bottom.
Too bad the dollar incentives are too low for this to actually work. You have no buyers, and the sea of open source software is your competition. The fully baked stuff, Matlab, Mathematica exists for a reason, it isn't just the algorithms.