Avantages
Can't beat the flexibility in scheduling. You log on whenever you want, can work as little as a few hours a month. You need to know your stuff (kids expect you to know the answers to complex math problems off the top of your head) but averaged over a lot of sessions, good work is recognized by the management.
Inconvénients
It is difficult to get hours. You often have a long wait times between students and sessions are short (you are pressured to keep them under 30 minutes) so it is hard to accumulate paid hours. On top of that you are capped at 4 hours per day. So even if you can hit your max your total pay will be low. I rarely hit my max despite being logged in 6-8 hours/day, except around mid term/final exam weeks. On top of that, the only time that is is busy is when kids are doing their homework, which is around 5-9pm ET. Hardly any students log on until school is out at ~2 pm ET. This makes it ok if you have a day job and want to work through dinner, but means it cannot be your day job unless you live in Hawaii. I had one really exceptional month in May during exam time where I took home $1000. Most months it is ~$300-$400 because I am logged in but there is no one to tutor.