You just add the one line of code to your pages. We're doing the rest!
We built this service for ourselves and here is why.
Google Analytics is a great tool but it require writing a custom client-side code if you want to understand how a user interacts with your site in details. And in most cases, it is not a trivial code.
It is an event which requires some reaction. For example, your customer fills only a part of checkout form on your site but did not finished the checkout process and just closed the browser. In such case, Formtrigger can send an email to that user with some proposal. Or, if the user just went to another page on your site, Formtrigger can show him a popup window. Then you have a chance to get such user back.