"Advantages & Disadvantages" of using a blog to learn English

Advantages:
    Using a blog you can meet people of other countries.
    Know diferents kinds of english, so you can extend you language.
    Is an advantage because you can share knows whit people of any geographic area.
Disadvantages:
    Some people just don't respect your purpose or your opinion.
    Do not know how to show your ideas, and it's very frustrating.