Since we seem to be sharing the numbers now, let me add my 2c. I ran the Hamachi service [1] with 3 mil registered accounts off 4 co-located servers at a cost

Since we seem to be sharing the numbers now, let me add my 2c. I ran the Hamachi service [1] with 3 mil registered accounts off 4 co-located servers at a cost of about $700/mo in total. The servers were mid-range 1U Dell boxes, each costing around $1K. That was back in '04, so I'm sure prices have gone down quite a bit since then. [1] http://en.wikipedia.org/wiki/Hamachi_(software) http://en.wikipedia.org/wiki/Hamachi_(software)