If you are a regular Second Life user, you may have noticed that they are currently experiencing significant slowdown and shut downs, almost on a daily basis. Access to the service is very often closed for "maintenance" or "emergency actions on the grid". It is said that they have a huge architecture issue and that SL might not eventually be that scalable, with about 3 users per server !!
My guess is that the architecture was designed a long time ago (SL is 7 years old after all) at a time when the company had little funding form VCs (let alone customers), especially after the dotcom crash the 3 years of nuclear winter after that. So they maybe had to cut corners, choose an architecture that was easier to implement in the first place, require less fixed costs. They maybe thought that dealing with huge scalability issues would be a good problem to solve later. Of course all this is pure speculation but this is what I would have done with limited funding.
Now they have to find a solution in an emergency (as described here). Problem is that this kind of architecture issues cannot be solved quickly, even with lots of money.
Maybe it is time for someone else to come up with a better more scalable technical solution ? Maybe Google with Google Earth, who knows ? Or Sony ?
Anyway let's hope that Linden Lab finds a solution, SL is great and they deserve to survive and thrive. (by the way you can find me in SL under "Mathieu Noonan")