Another reason is the flexibility. Because it's online, you can take it anywhere. Most students are attending at home, some at hotel during tournaments, and some on cars while their parents drive. It is much easier to transit into other activities, because the parents have no need to drive from one place to another place. It's very helpful when students have many more activities nowadays.
We are using Steps as our core curriculum. It's very easy to follow our schedule. We also provide video recording for each lesson in case your child needs to review or to catch up when s/he misses the lesson.
For current offering, you can check:
http://www.chessstepsonlinelessons.com/