This link will give you the information on the dif

This link will give you the information on the different Market Makers (MM), but ETMM=Etrade Market Maker and NITE= Knight Equity 

http://www.otcmarkets.com/otc-pink/marketActi...maker-info

You should research Market Makers on the internet.  Basically they are the companies that facilitate the trading of shares by buying and selling shares.  They hold an inventory of the shares and buy/sell them from/to customers (like you or me) and they basically make a profit on the bid/ask price that is quoted to you.  You can buy/sell shares at 0.0001, but they can make a profit in between this price by being able to buy and sell shares at 0.00001.  It is a bit complicated, so I suggest a quick read on the good old internet.