To be honest, it's a little weird. We always have tons of people that want their map tested, and tons of servers willing to test maps, but we never seem to have enough people willing to stop what they're doing and help test (at least not at the same time - you can usually average 4-8 ppl willing to test at most times of day).
I'm not sure what the solution is...but I honestly think we could find one if we all made a conscious effort to help establish an environment where there was more willingness to test each others maps...or a more consistent frequent testing schedule.
Personally, I'm still a big fan of developing a system where people get points/credits for time they spend helping people test maps - and those points/credits going towards preferential timeslots on testing days.
well...its not exactly surprising...
you can map when you have spare time, or whenever you feel like mapping, you can toss out servers for people to use no problem, but to get people together to test maps as a whole tends to require more effort then most people are willing to give, especially if you are going off of a smaller group of people. No one will always be free to test a map, nor will anyone ever always want to play.
There is not exactly that much that can be done about it...for an on the fly test you can get people on your friends list...but that is a slow process and never brings in a terribly large amount of people. Or a group event can be used, its easier to do but ends up with even less results as it is even more impersonal.
The best way and admittedly most difficult thing to do is to maintain a populated server where people can join whenever they feel like and that can take maps on the fly and get them going. Creating something like this requires a huge userbase though...and is something we are unlikely to achieve...
In my opinion the most accessible method for us is giving a mapper the tools needed to host a map test (server access, group chat and other such things) and make them responsible for populating the server...this happens to be the way it works now for the most part, it could be better, but it can work.