Tim Bray builds on a question by Tim O'Reilly: "What standard of open-ness can we apply to Software-as-a-Service offerings, to the Googles, Yahoos, and Amazons of this world?". His answer: Open Data.
At the end of the day, information outlives software and transcends software and is more valuable than software. I think any online service can call itself “Open” if it makes, and lives up to, this commitment: Any data that you give us, we’ll let you take away again, without withholding anything, or encoding it in a proprietary format, or claiming any intellectual-property rights whatsoever.
It seems to me that if you don’t have that, you have nothing, and if you do have it, you have, if not everything, at least a solid foundation to build on.
That’s basic, Level 0, openness. For extra credit, a service could also say: We acknowledge your interest in any value-added information we distill from what you give us, and will share it back with you to the extent we can do so while preserving the privacy of others.
So, do we need some sort of Open Service analogue of the Open Source Definition? It couldn’t hurt. I suspect that if we can get the basic idea across, then we’re in old-fashioned consumer-advocacy territory; and I suspect that it will only take a small number of painful experiences for consumers to understand the issue at a pretty deep level.