CTM is reliable. My agency has been using them on behalf of our clients and our own business for close to a decade.

Nothing specific comes to mind right now!

Easy implementation, very intuitive and flexible. Possible to scale without long term contracts. Pay per minute and not per user : turns it into a variable cost.

The tool doesn't manage automatic outbound calls (auto dialers) very efficiently. Not easy to run multiple callcenters in one account (work in progress)

If it would work, it would be useful in measuring offline conversions.

Tried working with them for YEARS to get the data right because if it was correct, it would be so useful. Once I audited the data, the calls had nothing to do with the keyword data that was being reported. Until my arrival, the company was making decisions based on CTM's INCORRECT DATA! I implemented every change they recommended, including purchasing more numbers and inputting more sources but it was never resolved. When we decided to leave, they had auto-renewed our account and promised to refund, but did not. Additionally, many of the calls at the end were robocalls or hangups.

We are able to easily purchase and set up multiple numbers quickly for different lead sources in a matter of minutes. I appreciate that installing the code onto a site is very quick and efficient - it's a matter of just adding a javascript to the header of the site! When you're working with hundreds of clients, and even more numbers - every second saved is worth it! Plus, their customer service is great and any issues are usually solved very quickly.

You can globally set a source, and then apply it to various numbers. However, if you edit that source, it doesn't roll out to the numbers it's assigned to. You have to go through and set that source again. When you're dealing with hundreds of clients, it can be a real drag to have to make those adjustments. I'd love it if they'd let you make global source changes, and then upon save, roll it out to every assigned number with that source.