Good question.
There is obviously some room in this market for taking advantage of another market's waste or to take advantage of one overhead in the production process.
If look at the meat industry for example, you have mechanically removed meats that satisfy other industries like reconstituted meats and after that petfood and petfood places is really only one supply chain link to fishing feeds, groundbait being something that must I assume contain to some degree an edible foodsource for fish beyond simply attraction, a bit like cattle and horses being used to make glue, gelatin, beef stock cubes, Bovril, shammy leather etc etc etc or to put it another way, one business's waste by product is anothers potential commodity, a little tweak in the market or some clever advertising is pretty much all there is to it.
Yeast extract is another great one.
I bought "sinkers" for my loaches and I swear they are the smallest Halibut pellet out there but not sold using the name of that fish.
I know a guy who buys dog and cat biscuits (because they are cheaper to buy than named groundbaits) and he prepares them in a way that to be fair produces a half decent ball of groundbait, and it smells like it has something about it too, being happy to continue to use it, even though its not likely to ever be properly tested against a leading brand or promoted by those in the industry.
Spent bread?
Funny thing that still gives me a chuckle, a bit off topic, is my old man used to rib my brother for buying groundbait and putting to much emphasis on it being the sole thing that would secure him a catch, my old man referred to it as powdered scented donkey ****
My old man always used scrap bread
