This question arise in context of Broadcast And Media Technologies, but it shares such a fate with many other proposals.
Broadcast and Media Technologies - is a very specialized industry where finding experts (even if you are willing to pay money) is very tough. And knowledge sharing is very limited. There are definitely very few forums.
Yet, I have managed to create a very consistent flow of people - going to almost each one after the other. It has by now, 68 members and almost 70% of them are simply new to Area 51 and Stack Exchange completely. This all after a lot of personal pain I have taken to invite personally.
But even as this, it is only a half of the half battle won.
Stack Exchange have an extreme number of restrictions and variety of clauses before things begin to work. I am not complaining - it is necessary to ensure a healthy site when it gets created. While much emphasis happens about what is permitted and what is not permitted, and on one hand when we say that Stack Exchange wants to invite experts, - I feel there is very little effort (specially from Stack Exchange) to actually invite and persuade these professionals and experts.
First off, unlike most forums, Stack Exchange is very different. This is great, but I don't think many people really understand these differences clearly and to the extent that they really come to appreciate and spread the word.
Many people are not even aware of Area 51 - and those who are first-timers to Stack Exchange - given the link of Area 51 following message, don't quite know these differences/relation between Area 51 and Stack Exchange itself. The FAQ right in the corner is something hardly a new user would notice and even if so - for an absolutely fresh user - it doesn't quite introduce what Stack Exchange is all about as opposed to Area 51; so your chance of elevator pitch is gone.
For new users, once you see that they have visited and interacted - you do feel like coaching them about this - however, there is no way to reach out, no emails - not even "Send message through Moderator" to tell them. For example, many people applies "Follow" - but most don't really bother to add questions. So many people who visited the Area 51 proposal, but didn't realize what "Upvoting" means. So in spite of all their enthusiasm we are loosing the opportunity to connect to them.
Often it is told that "chat" is a feature to engage them - but I usually never know when someone will knock at the door. And the time window is usually not more than 5-10 minutes - and I won't know if someone is online. Also the "chat" links right in the corner - is not even a strong feature for people to notice it. Most often, we don't quite get hold of people.
Area 51 - proposal page - are NOT real sites and not that engaging at the first place. Unlike a regular site where there is large enough content and people spend more time reading writing Q&A, there is hardly anything for interaction in Area 51 for experts who don't usually digress in so many other subjects. We (at least I) try to excite people through the concept of essential need of great Q&A site with high quality content - but there is really no content or interaction on a proposal page with merely five questions and upvotes. And after that - there is no further interaction! So all the excitement goes away.
Customer's don't quite return. Even if people managed to grasp some concepts, and wants to remain attached, they have no business to come back to Area 51. Most users don't quite come back unless there is some notification. Even if they visit on their own, they have no better thing to see other than the same question list and few more people getting added in the tally. I am specifically talking about the users who otherwise do not go to other Stack Exchange sites.
A typical waiting period (for most proposals) is far too high. In the web world, where typically people have so many networking sites, forums where you simply register, login and start posting - an average Area 51 site remain in hibernation/incubation for more than a years time put together waiting for other people to join. Customers - and specially if you are trying to invite experts - have certainly many better things to do in life than watching commit numbers increasing by 1% every time they visit here!
I am not sure, but almost certainly, Stack Exchange doesn't put sufficient effort to publicize this either internally or externally. There are ads you see about "Support this proposal". However, the matching is never really interesting enough to catch experts in the relevant area. It is not allowed to advertise anywhere inside Stack Overflow and the only thing that works is that the proposer keeps spamming on personally to make the proposal succeed. [why am I really taking so much of personal sweat to raise Stack Exchange's traffic?]
I am not asking that you abandon all the principles that makes Stack Exchange what it is. But certainly, we are creating so many artificial barriers and otherwise do very little to really attract the real experts that is essential to make any site grow.
Sites which are programming-centric gets to commitment phase within days because lot of young guys visit Stack Overflow daily. But in the very core areas - (look at Logic Design, Robotics, Computer Vision) we take more than 1 to 1 and half year and things completely saturate.
Take a look at so many sites in the Define and Commit stages from more than year - why would people keep coming back to you? Are we doing enough to woe them, engage them, motivate them to stay connected, or keep up the enthusiasm until the baby is born over years?
Please share your experience and views. Let me know how can we really reach out and educate new users?