You put a lot of thought into that...
Let me take a stab
Winter: You have a lot of holidays Thanksgiving, Christmas, New Years and then recovering from the season. Most haunts don't work on their haunts in the winter as most are not in year around locations or they simply wait for the haunt show prior to doing anything. People talk about the show coming up.
Spring: People show lots of photos of the show, talk about the post-show best of to looking for the next thing they need to build their haunt.
Summer: People post a lot of photos of them building their haunts, vendors talk about last minute deals and as always people are looking for information
Fall: Talk about how the season is going and then how the season ended up.
People now spend a lot of time posting and updating their social media pages like the new one instagram there is just so much information out there now its not even funny.