Trends in hosting: clustering and grids for hosts

Traditionally web hosting was done on shared hosts. The hosting company would get a large server, and sell space and bandwidth on it to customers.As one's site grew, they would go for dedicated hosting, where they have their own non-shared server.Later, there would be virtualized servers (VPS), which fill the gap between the above too, giving the customer control over their server, but still sharing the hardware.Now, several companies have started to deploy "clusters" or "grids", where a pool of servers is at the disposal of customers.The first company to do this is Amazon, with their Elastic Compute Cloud (EC2). The pricing of which is by instance-hour, GB of data transferred, and GB of data storage used.Media Temple followed with their Grid Server, and pricing is more conventional with a plan having certain limits for a fixed price per month.Lately, Mosso, backed by Rackspace, started offering clusters as well, on the pricier side ($100 per month for 80GB of storage, 2000GB of bandwidth).It seems this is a trend that we will see more of in the future.