a_laiho It depends how you want to go about it. The easiest way would probably be to add a Flarum installation on a subdomain, such as discuss.zoptamo.com (to use the URL you posted as an example).
As for whether it's worth it or not, that really depends on what you're hoping to achieve. Forums can be used to answer inquiries, provide support, or build loyalty and communication among clientele. But there are costs involved, too: an unmoderated forum can become a liability to a business, and good moderation takes a bit of effort.
The first thing you should do is decide what your goals are. What are you hoping to achieve by adding a forum? Your questions will be easier to answer once you've fleshed out your ideas a bit.
