There are companies who advertise that they will show you how to grow worms commercially. They will sell you the worms and the know how to breed the fishing worms. They will buy the worms back from you and advise you on the possible markets for your fishing worms, for example, tackle shops, local councils for composting and football pitches for soil restoration.
In my experience these Companies are running scams. The people selling you this package do not provide you with the correct information to grow the worms. In fact it is extremely difficult to grow worms. Worms will not thrive unless the conditions are exactly right. What is more likely to happen is that the worms will crawl away the first night of heavy rain. Or they will come to the surface and die because the bedding is toxic for them. Growing worms is a specialised occupation and successful worm breeders guard their secrets closely.
The market for worms is generally restricted to anglers and anglers do 80% of their fishing in the summer months. In other words, worm breeding is seasonal. I am not aware of any football pitch ever having used commercially grown worms to irrigate their soil. In fact, the worms used for soil improvement (lobs) are a completely different species to those promoted in these schemes (dendrobaenas).
Local authorities have experimented with worms for composting and while it does work it does not work fast enough to break down the large amounts of waste they have to deal with. Most local authorities have dismissed vermicomposting as a solution to large scale waste management. These worm growing schemes are sometimes targeted at farmers who are seeking to diversify from more traditional farming. Many of these people do not carry out proper market research. They do not for example realise that every tackle shop in their area will already have a supplier of worms.
Many people have had their fingers burnt with these schemes. Caution is needed before embarking on a worm growing business because fishing worms are not easy to grow. If you do decide to go ahead, do not buy in large quantities until you are confident your fishing worms will not crawl away. Finally check out your market and competition before parting with your hard earned cash!