paying $17 to upwards to $170 for a statue of a robot, even a custom made one, is a rip off. But that's the pitfalls of custom 3D printing. Even something simple, if you want it now, becomes prohibitively expensive. Overall I think the robot builder idea linked above is just ill fated. You need some other reason than "custom" to drive sales. Something that is a a part of a larger game, like D&D minis, would make sense to me, or a print of your World of Warcraft avatar or Minecraft creation, a little monument to your ingenuity and time. Still, not $170 worth of sense to me, but at least a little more sense.
I understand that the people at Cube used the service in their Earth Day celebrations. Tho "robot" and "Earth Day" make for strange bedfellows, unless we're talking about Laputa, in which case that's cool.