This week, LL posted some upcoming changes to how Second Life regions will manage avatars.
Since the dawn of time, SL regions have had a maximum number of avatars that they will support. For full regions, this is 100. It's less in Homestead or Openspace regions.
Access has always been first come, first served. Anyone can get into the region, but if it reaches its capacity, no one else can get in until someone who is there leaves, making room.
But Linden Lab is making some changes to that. First of all, region owners and managers will always be able to get in, even if the region is at its maximum capacity.
Second, and perhaps more significantly, the maximum capacity of regions is being increased. Instead of 100 avatars, now full regions will allow up to 110. Homestead regions go up from 20 to 25, and Openspace regions from 10 to 12.
But there's a catch. The new higher capacities are only available to Premium members. If you are a Basic member, and a region you want to get into already has 100 people, you will still get the "Region Full" message. But your friend who's a Premium member will be able to get in.
Probably a fairly minor Premium benefit, but they do add up.
Read more about this change in the official Linden Lab blog post: https://community.secondlife.com/blogs/entry/2145-improved-region-capacity-and-access/