In my opinion it is an option or an alternative and not an effective strategy, the reason I chose to parlay is because just to get the big odds and the parlay is an alternative for me and the parlay is totally ineffective because you have to win all bets. If you are looking for effective strategies, I would prefer to bet single with intermediate odds.
I see if you are confident, then go for the parlay, if you are willing to take the risk.
For any gambler who are by nature impulsive, the parlay option is a profitable one so it seems. They often become overconfident and want to make a huge profit off some small balance so they go for all those bets which have their favorite player and bet on them. These commonly end up in a drastic busting but they really dont care because they are addicted gamblers.