Picking the right category with the Local Business Center is one of the keys to success in Google Maps. Categories are critical to being considered relevant on any given search and should be chosen carefully to meet your short and long tail priorities. Since a business may only enter 5 they become very important.
Given the way that they are presented, it is difficult to plan ahead which categories might be the most appropriated for you or your client’s listing.
Here is a complete list of every category and synonym that Google currently provides within the Local Business Center. At some point in the future, I will provide the information in a searchable database to make it more useful for planning purposes:
On the list you will find 2239 categories which includes plurals ie lawyer and lawyers as well as certain geographic place categories like “estuary” and other geographic phrases. The fact that the categories include both singular and plural should reinforce the sense that you need to pick the ones you need for your listing carefully.
When the Local Business Center was first released Google only offered a choice 450 categories and no custom categories. At the time if you used any of the limited categories offered in the LBC, Google would use those to supplant any that had been provided by the Superpages. So the upshot during that timeframe, was that you had to remove ALL categories from the LBC to get into a given Superpages category in Google maps results.
In March of 2008, Google subsequently went to a more free form, expanded categorization structure, initially not requiring the use of any of their categories. This summer, Google started requiring that a user select one preset category and then allowing for 4 additional preset or custom categories.
I would love to hear how you use this list.