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I can think of these factors:
1. put the address on the website (preferrably in a way that it can get crawled ;))
2. Submit to Google Maps.
Is there anything else that can be done? I've been wondering for a while how they created those local search results with the map....and how important it is to get listed next to the map in the first place (maybe nobody clicks on them, yet, maybe they take 90% of the traffic?)
Some phrases are more likely to invoke the local one-box or ten-box than others.
For instance, city names with two or three words in them like "Los Angeles" are slightly less likely to invoke the treatment than others, because it can be slightly harder to for Google to discern what the query is about. Also, if the phrase includes the name of a common business category like "plumbers" or "restaurants", then it's more likely to invoke.