Get tips on how to make your own furniture,
find companion runners for the next city marathon or discuss dog
training techniques – there are online communities beyond Facebook for
all these and much more.
Online communities as a forum for discussion and trading information had their heyday in the mid-1990s when anyone with a PC and Internet access could contribute on almost any topic.
And today? Forums have taken a big hit from Facebook in terms of membership, but they're still around.
"Online communities are still in vogue," says Professor Herbert Woratschek from the University of Bayreuth in Germany. "However, the quality of what's offered and the number of members is highly subject-specific."
The most popular topics include cars, sport, pets, travel and cooking.
One of the reasons for the popularity of Facebook is that after a single registration you can receive content on a variety of topics directly to your computer or smartphone, whereas in the case of the classic forum you have to register for each new community.
But there are also technical reasons for the shrinking popularity of online forums: "Many communities sleep through technical advances such as mobile capability and content trends and disappear slowly but surely from the scene," says marketing expert Woratschek.
However, compared to the social media top dogs, online communities score with more depth and topic relevance. And topics can be deeply discussed, often to the greatest degree when the topic is obscure.
"Highly specialised special interest topic pages are still extremely popular," Woratschek says.
Sports forums are particularly popular and can help people find training partners and teams in their area, whether for body-building, running, cycling, football, climbing or any other sport.
There are also plenty of auto forums dedicated to classic cars, motorsports and car repair.
Do-it-yourselfers and hobbyists can also get their money's worth in communities. Sewing your own clothes, making furniture out of timber pallets or turning your balcony into a vegetable garden - there's something for everyone.
"Our community is alive, its membership is growing, even though most of the content is generated by a small number of regular visitors," explains Berno Delius from a DIY forum in Germany.
"Nevertheless, we feel a migration towards Facebook, of course, but due to the active participation in the DIY forum it's not so important."
This trend of migration towards Facebook is visible across most online communities. For example, Zooclub, a forum for pet lovers where you can create profiles of your animals, has around 13,000 members on its website, but 100,000 on Facebook.
Even so, the forums still offer benefits for those willing to get involved and dig deep, especially for more specialised topics.