If I have a paid blog at wordpress.com, can I install plugins manually on it?
Or must I have my own wordpress installation?
Questions on WordPress Development Stack Exchange are expected to relate to WordPress within the scope defined by the community. Consider editing the question or leaving comments for improvement if you believe the question can be reworded to fit within the scope. Read more about reopening questions here.If this question can be reworded to fit the rules in the help center, please edit the question.
Short answer - no, not really. Though there are already a lot pre-installed and you can suggest new ones if you'd like. Check this article out: http://en.support.wordpress.com/plugins/