Spam 10:1 rule

Could someone clarify the 10% spam rule for me.

I'm confused as to whether post and threads are counted separately for this rule.

I comment a fair bit but I rarely post threads and when I do its usually self promoting, is this a problem?

If I posted 9 normal comments and 1 self promoting thread would that be okay or does it need to be 9 normal threads for every self promoting one?