Seems there has to be a better way other than forced participation...maybe we can turn this into a suggestion thread 
Some people are too busy to contribute monthly but still enjoy popping in with a contribution at their convenience
So...
Minimum Posts - 50 posts distributed evenly over 6 months (current policy)
Minimum Years Joined Alone
Minimum Total Lifetime Posts
Minimum Total Lifetime Posts + Minimum Years Joined
No Minimum

Some people are too busy to contribute monthly but still enjoy popping in with a contribution at their convenience

So...
Minimum Posts - 50 posts distributed evenly over 6 months (current policy)
Minimum Years Joined Alone
Minimum Total Lifetime Posts
Minimum Total Lifetime Posts + Minimum Years Joined
No Minimum