Personally, I am still waiting before doing any announcement. (See
viewtopic.php?f=24&t=8&p=215#p215)
It's true that there are few members, but they are high quality! (But we could do with more contributions - see
viewtopic.php?f=24&t=15) And, it's relatively new - we should expect growth to be organic.
In my view we need to continue to make posts, especially with pictures and explanatory text, so that when people do come, there's something here to give them a reason to register. At some point there will be a sufficiently attractive post that there will be an influx of visitors: a good discovery and discussion which is then mentioned on Hackaday for example.
It's a good point about the oneline description. How about
"For people who build computers from microprocessors: if it's not 6502.org, it's anycpu.org"
Cheers
Ed