Glassdoor is a great site compiling all the important and interesting details about various companies. You create a login, enter your own salary details, reviews etc. and voila, the full compilation of data from other users is avaiable to you.
So, it a service similar to what Vault provides, but its free. I am sure Vault provides much more. But really if you want sufficiently exhaustive salary details split by roles and location (and also perks), then there's enough data on Glassdoor
The reviews about companies are really informative. There are interview tips and tricks which will also help you prepare in case you are looking at switching :-)
The reason for this blog is to advertise Glassdoor so we have more reliable and accurate data points.