Most communities don't try to be great. There is a way to tackle this, aim for big wins.
One of biggest wins is to have influential people participating in your
Here is a simple process. Make a list of all the key influencers in your community's sector. There are four types (1) Fame (most well known) (2) Authority (most direct power) (3) Expertise (most knowledgable/skilled) (4) Relationships (most connected).
You can find these people (if you don't know them already) by reviewing the major publications and blogs in your sector. Find out who they are writing about them.
Build up a list of the 20 biggest influencers. Your research should also include how to contact them.
Now, write to them on behalf of the community. There are many things you can ask them to do. For example, invite them to participate in sfuture live chats, interviews where members get to submit the questions, contribute guest posts or merely comment from time to time on topical issues. Mention other people that have agreed to participate (or others you are approaching).
Repeat this every few months. Don't hesitate to use the phone to contact people. Your progress will improve over time. And you will get better at the approach.
Just try it, you never know who might say yes. One big win leads to others….
Bonus: If you want to be sneaky, publish the list. Send the link to the influencers. Let members vote on who, of the 20, they think are the most influential people. You can guarantee every influencer will read it.