Yep if the liquidity increases too much and the spreads are reduced to nothing, this current bot won't be able to earn so much. It's just coded to stop trade on any too liquid altcoin. I have the project of making another type of bots for really liquids markets (like USD BTC) but it will take some time to finish it.
So I guess it's "spread bot", what you'd call a dealer in traditional stock markets
that's interesting because I was thinking about coding one, there is plenty of not-so-much liquid market on medium market cap coins
but you still have to guess how the market will "move": will people tend more to sell at your bid or to buy your ask. how do you manage that without human supervision?