Anyone have experience with sumo.com?

Reading this article: https://sumo.com/stories/0-10k-nat-eliason?src=facebook-story-0-10k-nat-eliason#2.

It seems to have a ton of good information. I plan on reaching out to them to see if they will help me promote my Chrome extension, wondering if anyone has had experience with them?

Also, it seems like they offer some neat plugins like this, https://sumo.com/app/welcome-mat, that offer email sign ups on page. Can anyone recommend another landing page email signup widget plugin? I could build my own from scratch but seems like this should have been solved already.