Paylocity was the first customer that Soma Somasegar, Corporate Vice President of the Developer Division at Microsoft, mentioned during Microsoft's virtual Visual Studio 2012 launch!!!
In addition to citing what Paylocity is saying about VS2012, Microsoft also released another case study on Paylocity -- this time focusing on how we are using Visual Studio 2012. Originally we adopted VS2012 to start creating mobile apps with MVC 4 / HTML5 / CSS3 / PhoneGap, but what we found was that there are so many enhancements that this is a must-upgrade release of Visual Studio!
For more information, see Microsoft VS2012 Paylocity Case Study. While the recent case study focuses specifically on Visual Studio 2012, Microsoft's SQL Server group published a more comprehensive case study on Paylocity in 2011 which can be found at Microsoft SQL Server 2008 Paylocity Case Study.