I have made a business out of mine. Well, an illegal business, since I don't report profits, nor pay taxes, lol.
I have the expensive Disney Brother machine. I don't think I will ever embroider enough towels for myself to get the 4000 EUR worth out of it! And at the moment I (well, my parents) bought the machine, I didn't have a job. So, I made publicity with friends and family to embroider for them.
Now, 5 years later, I still do it.
I have a folder with all the designs I have (or at least a selection, I have 150k + designs) and how much it costs to have it embroidered. The lady from the store where I bought the machine told me that she charges about 50 cents/ minute of stitching (the machine shows how many minutes it'll be) for designs and to charge per letter for names/ dates/ ...
(btw, 50 cents => it's in euro)
If I stitch somethin occasionally for my brothers, if it is for them personally, I don't charge. If they need it as a gift for someone, I do charge. All the others know it's a business, so they expect to pay.
I usually stitch on towels. People can come with their own towels, or I can provide them. There is a store that has good towels that aren't too expensive. A small towel is 3.30 eur in store, if people order it from me, I charge 5 eur, because I have to go to the store and buy it (spend time doing that + pay for a train ticket to get there) (I do have a stock of the "standard" colours though)
This little business makes some nice money, to spend on things like Disney!