This article explains the local ecosystem and how it is connected.
The local ecosystem is very varied and it is also connected. In the table below we summarise the most important platforms and the connections between them.
As you can see, some of them allow users to edit your data directly (which is why Change reports are useful) and some serve as data sources for the others. It is commonly accepted that having consistent data on them can actually increase your relevancy on the others.
We always recommend being at least on Facebook & Google, plus on a data providing site like Factual. You can extend your presence to related platforms like Foursquare, Bing, Apple Maps and Yelp. In the case of given verticals, there may be other platforms you'd like to have a presence, such as TripAdvisor for hotels and restaurants.