First of all, it's a high quality, professional plugin, didn't have any bugs etc...I have used it on vBulletin and Xenforo boards. The newsletter never went to spam, I never got complaints about the newsletter. It's relatively easy to use and any time I had any issue Threadloom's support was very good and fast to respond. They have accurate analytics which you can confirm by comparing with google analytics. I have a board with 100k users and I was getting ~200 clicks from the newsletter everyday while only doing 1 newsletter monthly.