Ask HN: Are XFN links and FOAF popular enough to base a startup idea on them?

[SingAlong]

Just a few hours ago I read http://paulgraham.com/ideas.html

The phrase "idea from a shower" caught my eye and in very little time I could see myself brain-storming ideas on paper. I like one idea which uses XFN links and FOAF. But are they popular enough to base an idea on them? Is is possible to urge people to describe their relations with XFN and FOAF by adding it in the plugin that I develop?

To be precise, my idea isn't new. It's just what other few startups are doing. But in a different way: by utilizing these XFN and FOAF data.

[tonystubblebine]

There's real momentum behind data portability and that's likely to help all standards. However, I was very disappointed, when we were implementing FOAF, to find that the FOAF validator is broken. I took that as a sign that people had moved on to other standards (XFN+hcard).