I like that it is very easy for me as an employer or recruiter (or any user) who wants access quickly without having too much knowledge about how things work! Also they have great customer support which makes everything run smoothly even if you don't know what's going wrong when using their service!! If there was more flexibility around search queries - i think we could do better than just getting results back sorted alphabetically but not necessarily chronologically.
We are able get quick insight into where people would be interested/available at different times during day / week etc so can make decisions easier regarding hiring process & recruitment campaigns.