It’s mostly intended for places where data is going to be slurped out of a database and dumped into a template or renderer. Adding a bit of extra gunk to the template isn’t the end of the world (especially if you have a sane template system).
If I’m writing some text by hand, I’m going to use markdown and just write:
# Hendershot’s Coffee Bar
1560 Oglethorpe Ave, Athens, GA
As for the benefits: having some widely-used machine-readable metadata linked directly to the data could let browsers do some pretty neat stuff in the future, like letting a user click to add an event to his calendar, look up directions to an address, or add a person to his contact book.
Kilimanjaro's JSON data-island example is certainly more readable. OTOH, with that approach there's the risk that, during maintenance, the data island will be overlooked and will become inconsistent with the human-readable information.
Edit: Perhaps that risk could be mitigated by having the human-readable markup issue a JS call to the data island, which would have the benefit of being DRY-compliant.
If I’m writing some text by hand, I’m going to use markdown and just write:
As for the benefits: having some widely-used machine-readable metadata linked directly to the data could let browsers do some pretty neat stuff in the future, like letting a user click to add an event to his calendar, look up directions to an address, or add a person to his contact book.