Also, I'm sure you've already considered it so probably no point me mentioning it, but would be interested if you could share your reasoning for not offering the free credit like Twilio do. As a single point of data, I signed up for Twilio and started playing around because of that offer (even though it meant putting a little in myself), despite having no use for it at the time. Without it I probably wouldn't have bothered, whereas now I'm someone who, while never had the need to spend more than a few dollars here and there with them, am happy using their service as my go-to whenever I need any voip/sms stuff.