Aggregators essentially lease their data to a long list of different sources. This can be a mix of directories, GPS services and online applications. Because of the nature of data leasing; the distribution network is constantly changing. 

Here's the most recent copy of the aggregator's distribution network, this is from Q4 of 2015 so certain sites may have dropped out/ in since this was put together - nevertheless this should give you a good idea of what it is in the aggregator submissions.