If members aren't interact with each other, it's tempting to add more features.
Add a regular blog to the community, add competitions, add an ask feature, add an upload photos section, add a referral feture.
Before long, you have a community that looks a littlie like The Glenlivet
If members aren't interacting, the solution isn't to add fringe features.
At best, they provide a blip of activity (if heavily promoted), at worst they are a distraction from current activity.
Extra features don't 'increase the value' of the community. Members don't rationally way up the pros and cons of participating before deciding whether to participate. They look for interesting discussions to participate in.
If members aren't participating, the reason is simple. Either they can't see/aren't aware of the discussions, they aren't interested in what is being discussed, or they don't have anything to say.
The solution to the first is structural. You need to change/tweak the site and notification features. The solution to the second is tactical. You need to initiate and facilitate more interesting discussions. The solution to the third is growth and education. You need to reach members that can answer these questions and educate the community.
…but it's never to add more features. You only add more features when activity is going well.