People want to see if there's a market of tiny hardware hosting, and if yes, be first to develop necessary hosting technology (e.g. power supplies, relay boards for remote reboot, optimal RPi mounting on the server blades etc).
It's a loss leader, host the Pi for free, then sell the reboots, SD card swaps, extra bandwidth, IP blocks....
Eventually upsell the customer to a full hosting package if they had used the Pi for an extremely cheap hobbiest/project/dev environment before going to a real server.
Eventually upsell the customer to a full hosting package if they had used the Pi for an extremely cheap hobbiest/project/dev environment before going to a real server.