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Google actually has a feed from major YP providers, therfore it is not a crawl like previously thought and more a data source for assured responce and verification source for crawled data.
Yes, you should start with Axciom and InfoUSA, but you should concentrate on the external proliferation of accurate business data accross all authoritative aggregation sources of business information.
Look for your business in G Local, and if it is not there or it is not accurate, use their new Local Advertising Center to rectify the problem.
YP data is great for population purposes- assured responce of sorts. The qualitative determinations of relevancy come predominately from other sources, specifically in pure search environments.