The ease of use, how well it integrates with Google AdWords/DoubleClick for PPC campaigns as well as other third party platforms like Facebook ads. It's also very easy to set up new accounts in different countries (and currencies) without having to worry about currency conversion or manually updating rates every time you add another account. I wish there were more reports available out of the box but this can be easily added if needed. We have been able to improve our ROI by being able to see what part each channel plays within the overall campaign. This allows us to make better decisions when making changes to any individual component.