I have looked at some of the most recent proposals that managed to survive the gruelling Area 51 processes. I will use the short form: q/d = questions/day (I'm trying to fit everythin on one line each):
- iota. Finished "Definition" within 2 days, but took 5 months (Jun-Nov 2017). Now has 0.4 q/day.
- Constructed Langs. Defn took 11 mnths (Jul 16-Mar 17), Commitment took 11 mnths. 0.1q/d.
- DevOps Definition took 10 months (Apr 2016 - Feb 2017). Now has 4.7 questions/day.
- Esperanto Definition took 6 months (Feb to August 2016). Now has 0.4 questions/day.
- Quantum Computing. Defn took 10 months (Feb-Dec 2017). Launched without meeting commitment criteria (got only 114 committers/80 with 200+ rep, in 3 full months, but commitment criterion was waived due to having a sponsor). Now has 4.4 questions/day.
By far the most successful of these when the public betas were finally launched, were DevOps and Quantum Computing. These both took 10 months in the definition phase, and quantum computing did not even reach the required number of committers.
The criterion (in practice) for graduating from public beta, is 10 questions/day for a sufficient amount of time. The data above indicates that reaching 40 questions with 10 upvotes within 4 months, doesn't seem to be the best indicator of a site that will attract a lot of questions/day, as the two recent sites with by far the most questions/day would have badly failed this criterion. Reaching 200 committers (100 of them with 200+ points) within 4 months, also doesn't seem to be a good indicator: Esperanto and DevOps were the only ones that satisfied this criterion in my above study, but Quantum Computing gets 11x more questions per day than Esperanto.
Has anyone looked at other indicators of a site's potential success? For example in Materials Modeling, we had absolutely ZERO example questions closed, and ZERO example questions with a net score negative, indicating the the people asking questions do know what they're doing (having spoken to many of them, they say that they use StackOverflow very very heavily as consumers, but they do not contribute much, so they don't have 200+ reputation). Has anyone that's been following Area51 for perhaps longer than me, noticed another site do very well when the questions performed well, but didn't necessarily reach the criteria within the new 4 month criterion? How about the "committer roles" data? Materials Modeling has more than 50% of its committers being either experts or academic-level researchers -- for those who know the other proposals better, how good is "committer roles" as an indication of whether or not a site performs well? How about the "committers also active in" field? 25.4% of the Materials Modeling committers are also active in SO, is there data to suggest that this might help, compared to sites where the majority of the committers are active in more obscure or more rarely used sites?