CartStack has been a pleasure to work with. They have a great product, that's focused and which works as advertised (if not better). The support is top notch; always responsive to questions, ideas and requests. Compared to a lot of other larger companies who offer cart abandonment technology, they have a much more affordable solution that's agile, and just plain works. I'm looking forward to seeing them grow. Oh, and it actually does work, as we have seen instant results for all sites we use their solution for.