A "Serial Poster" is typically a Facebook addict and a narcissist who compulsively will add a new post about their self every hour or less. This is for the purpose of validating their own importance to a dwindling audience who is increasingly censoring them as their enthusiasm fades away with each new self absorbed post. The Serial Poster also will have a core group 3-6 unconditional fans who will "Like" indiscriminately each post that is made regardless of it's pertinence or relevance to their own opinions.
Everyone is sick of your self absorbed posts, you have become a serial poster.