A fair number of winners so far had 1 or very few posts. I'm not sure, but it's quite possible that only 1 user entry per person happens on the ECF part of the contest (this
thread). Additional posts are good, fun, keep the "buzz" going, but may not impact people's likelihood of winning. I don't recall if SmokeyJoe or low_tar_neil posted anything specific about this.
(The social media part, for the other 200 sets, does have higher odds based on how many "points" someone has. I've got my 10 points for initially entering, that'll be how many I have on Friday

)