[evgen]

Probably as often as the data provider(s) that Google is feeding into their system as well. You didn't think that Google was actually collecting that info directly, did you?

[mhansen]

Google does collect data directly, too. If you're a business owner, you can upload your business location and data here:

http://www.google.com/local/add/g?hl=en-US&gl=US#phonelo...

[moultano]

That doesn't answer my question . . . It wasn't rhetorical.

[culturestate]

I believe he answered your question as well as could be done without some inside knowledge. We don't know how often anyone's db is updated, so with no benchmark how can a fair comparison be made?