Probably the most cost-effective way to learn a language
This has to be the most cost-effective way to study Mandarin Chinese (although they teach other languages too) online, in small groups, following a program and not just random classes, and with a flexible schedule. Cons: If you really want to study with just one teacher all the time, this is not for you. (Having multiple teachers is how they can give you schedule flexibility). *You can always avoid a specific teacher for future classes if you didn't like him/her. I recommend it!