According to this new Starcom Mediavest study (see below), post frequency seems to lead to fan attrition.
Even if impressions & reach grow strongly inline with post frequency, an increase from 1 to 2 posts will result in a 46% increase in unlikes.
Quite understandable, the more you post, the more your visibility in your fans news feed increases. Thus the more they are reminded to unlike you if what they see about your brand doesn’t suit them.
Therefore, be very careful when doing a post-by-post analysis of their impact on your fans churn.
Correlation doesn’t always mean causation. if you publish a very engaging post (with lots of likes and comments), it will increase you overall visibility in your fans news feed. And if people leave your page, the main reason may simply be that, this time, they’ve seen your posts, unlike before.
Consult the whole study here.