If a colleague needed a platform with fast customer service and detailed reporting to sell their mobile inventory then I would recommend Rubicon Project. However, if my colleague needed a platform that gave instant current reporting data then I would be less likely to recommend Rubicon Project to them.
AdButler is suitable for any company size but I would said that it is better for small to medium-sized agencies. AdButler is highly scalable but the control panel/dashboard could be challenging to manage if you have many campaigns or many users. It's also a good alternative for ad networks, which would like to manage multiple relationships with publishers.
Cleanest supply ecosystem. They are skilled at processing inventory and bids in order to streamline monetization and drive yield.
Client support is excellent. Client services is deeply invested in your business and successful at driving key business goals within your organization when working on your behalf.
AdButler is very convenient and very cost effective. Additionally, when you change a setup at the ad level, the server shows the change immediately; there's no delay. Ad Manager is better when you manage a significant amount of campaigns and users, but it's not that cheap in the end and you always have to wait for any change. EPOM is also a good solution, but the look and feel are old and it's complicated for some users to manage properly.
Rubicon Project has made it easier to optimize so that we could get the fullest ROI on our inventory through their alerts on which deal needs troubleshooting.
They also send a daily report which notifies you which advertisers have low render rate which is very helpful when figuring which creatives need to troubleshooting.