apparently u need to either make the mob like u or fear u in order to improve the capturing rate, if not the rate of success is really low like 5%, theres also the cost of the capturing scroll. then there is stats/skill set/hidden stats(potential and etc) that the monster spawn with, which makes them more valuable than others. At the start of this launch many summoner quited cause it was too hard to start off(needed a party to bodygaurd u while u catch mobs, what was explain earlier, and etc), but those that did stay as a summoner later found out how op the class can be. there were also some who stayed a summoner cause they just like having pet/companion that isn't humans