It all depends on how data is aggregated and how specialized service like yours cater to the data i.e uses that data. For example linkedIn takes all the data f

It all depends on how data is aggregated and how specialized service like yours cater to the data i.e uses that data. For example linkedIn takes all the data from the end user whenever there is communication event. 1) adding a profile: name/school/college/specialization/job industry/company 2) adding a new job- job industry/company 3) adding a contact - type of relationship 4) asking a question - mark that to industry vertical/set of people So having granular details (which would help your service to serve users better) defines what data you need to collect from start and then you can use the same. pure speculation is cooler with above set of data