Currently even though Google is only showing 1 or 2 cats and I hiding the rest, I believe she’s reading them all and ranking them all – even uncommon cats.

PLUS there is a way to see hidden cats – if you need to see if a listing has a specific cat and you don’t have access to the dashboard. (As in doing competitive research.)

If you search City + Category in G Maps it will show you the category EVEN if it’s hidden on the G+ Local page.

Example: Denver Sedation Dentist (A custom/non standard category)
http://goo.gl/maps/QFtnD

Maps search shows the ones that have that category listed in their dashboard. But if you click to view their G+L pages, most just show the generic category Dentist or some other cat.

So to me that says Google is still reading and indexing those cats even though they don’t show on the listing currently.

The same thing holds true after merge – providing you already had cats entered in the Places dashboard. They’ll show with the right map search.

After everything upgrades to G+ and the Places dashboard is gone – who knows for sure. My spidey senses tell me the ability to select categories may go away and Google may use whatever 3rd party data she feels is relevant, to categorize the business – just like she does with G+L snippets. (Which as we know are sometimes wrong.)

At this point, the G+ Business page DOES NOT override the categories created elsewhere in the system. IE MM and the Dashboard are still feeding the beast.

The reason to link to the +Local page would be for reputation management and front page exposure, particularly on branded search. Beyond that I can not see a reason.

If you read the Location Prominence patent you will see that they define an “Authority Document” which is the website for the business or if they don’t have one then the most prominent business listing. The relevance of a listing comes from the categories, the business name, review content and the content of that document. If categories were to go away there may be additional signals directed at the website but they would not be about the G+ Local page or inbound links to it.

Great question. At this point, they seem to still be relevant.

But… if you notice, categories are nowhere to be found in the new G+ interface. In fact in that interface you are not even allowed to select a category with any granularity at all. You are only given an option to indicate that you are a retail store or a restaurant.

Also note that the main interface to create categories, Places for Business, is going away. I don’t know exactly what that means for the future of categories. But if categories are no more in G+ and the dashboard is gone then some future change might apply to both standard AND custom categories.

What’s Google got planned? Who knows. For now categories and custom categories are relevant. What the future holds is unclear.

They were clairvoyant…not us!