Why did you first make an LJ account?
To read what my "real-life" friends were posting, and to comment non-anonymously on them.
To read what my online friends or communities were posting, and to comment non-anonymously on them.
To read stuff written on LJ by people I didn't already have any sort of friendship with.
To keep a journal/blog that my "real-life" friends could easily read.
To keep a journal/blog that my online friends could easily read, and/or to participate in communities.
To keep a blog that I wanted people I didn't know at the time to read; to build an audience.
To keep a journal online, though I wasn't expecting anyone to read it at the time.
Because I worked for LJ, and it would've looked bad if I didn't have an account.
None of the above.