Sometimes, yes, and sometimes it's the same entity, but really MM stands for "Market Maker". These are big companies, often affiliated with banks or brokers, whose entire job is to make sure that options exist so that they can be traded. If you look at all of the available options, you will see that there are lots that have 0 "open interest" and yet there are bids and ask prices listed. The market maker will serve up the option contract if you want to buy one. This is why they have the famous "Madoff Exemption", that allows them to sell uncovered calls.
I use this myself but only for relatively short term options (because one day their value might go to zero), and only to get my initial investment back. If you diligently apply this rule every time the price doubles, you linearize what is fundamentally an exponential process... you get back the number of times the price doubled instead of the product of the doublings.