Despite having fairly good service at the spa, we provided an e-mail address so they could send an appointment reminder. After doing so I started getting spammed from hand and stone. I tried to "unsubscribe" multiple times, but I keep getting marketing email;s from them. I called the spa and they said they said the removed me, but the emails continued. Finally a very nice manager said their notification service (demandforce) was doing it and tried to get me removed. Ultimately I received a message from demandforce that they removed me. I still am getting daily multiple unwanted spam from them. I am marking them as spam on my web-mail, and if it continues I will report.
Conclusion, please feel free to use there service, but be warned that if you provide an email, you coul;d end up getting spammed.