Interactions (CLOSED)

This may be old news but I could not find an answer.  I was enjoying posting images (and links in the submission to vender pages) and watching my interactions gradually climb.  Of late, the interactions have been gradually declining.  I have read elsewhere speculation that this is occurring because one of the associated products or its vender has been removed from the site.  Other speculation includes site maintenance or cleanup.  Neither of these are entirely believable.  I would like to know the authoritative explanation.  Thanks.