A lot of good points raised in this thread
I started my board in February 2010, the activity has had it's ups and downs, but I have persevered over the last 5 years, I now have people come on there to post, mainly because I do dog training days and we talk about the training days, I am also a photographer, so I end up with a lot of photos for people to look at, the people who come to the training days like to go on there and see the photos & 9 times out of 10 they will leave comments, I also have a section for people to talk about training & diet advice & every now & then I have a photo competition with real prizes, the photo competitions have their pros and cons, the pros being an influx of new members joining the forum and taking part in the comps to win "free stuff" but the cons being some of the same people tend be to what I call "hit & run" meaning, they join for the sole purpose of entering a photo competition & then never come back, I also have a system where by people can't post until they have made an introduction, if they fail to do this after six months they will be deleted, they agree to this when signing up............ ok I'm running on a bit now, but I guess the point I am making is like many others have stated in this thread, keep your board special, keep the content exclusive ie; don't post it on social media, but more encourage your FB friends (if you use FB, I don't) to look at your forum, some will "like" the post and bugger off, others will probably stay & above all keep the gimmicks to a minimum, install extensions that will make the board easier to use rather than just making it look pretty & try to refrain from making too many sections as this will result in posts being split up, keep the sections in proportion to the amount of people using your board.
Anyway that's my view on it, it's not always going to work but you have to adjust it, as times change.
Take care.
~John~