A good teacher or an attentive student will be the same on or offline ,the advantage of the internet lies in providing a great opportunity for more flexible scheduling and transcending all distances,so it is very rewarding if both teacher and student are dedicated and both making the best use of the online auxiliary tools helping to create a diverse and rich experience in learning .

In order to learn a language effectively you should use a range of experiences. The internet is versatile enough to provide you with a wide range of experiences. You can find formal lessons on Youtube, you can use a range of language learning sites like Duolingo and Livemocha, or you can use phone apps like Mindsnacks. But the best way is to find a language exchange learning partner and have a conversation on Skype which is mutually beneficial.

I've taken Internet lessons from several instructors and have found them excellent. They use Skype with video. The video allows me to see facial expressions, body language, and gestures with the hands (and vice versa). They typically know how to use other Internet tools as well. For example, I find it quite helpful to have a Google Docs document open, and to be talking with the instructor while both of us can type and edit. I find it extremely helpful to have Skype instant messaging open at the same time as the video window. Often my instructors will type corrections as I speak. In fact the combination of talk/listen at the same time as read/write seems very useful. Skype has screen sharing and one of my instructors uses this feature skillfully to present visual material.