We are on-boarding thousands of new users every week, and with the projected launch of Communities and SMTs (hopefully later this year) those numbers have the potential to explode exponentially.
With little-to-no guidance from stakeholders though, these new members essentially resort to throwing stuff at the wall, and seeing what sticks. This results in a very high amount of SPAM, and a low amount of quality contributions that are actually adding value to the community.
I think you have this backwards. I think we're onboarding dozens, or perhaps hundreds, of new users per week, and at the same time thousands of spammer accounts who are creating them solely for the purpose of spamming. Maybe there are a few users who show up and don't know what to do and eventually end up spamming, but the vast majority of the spam is coming from accounts created for that purpose.
I'll think about the actual question in a bit.