I'm also really interested in using Sencha io, looks awesome (and not very expensive for now ) but saw those limits in the terms : Quota & Limits
Sencha has certain soft and hard limits in using its service. Hard limits are automatically enforced by the Service. Soft limits are consumable resources that you agree not to exceed. You may enter into a written agreement with Sencha that supersedes these limits, in which case that agreement will control.
Network Bandwidth: 2TB/month – Soft
Shared DB processing: Max 200msec per second CPU time – Soft
Request Length: 30 seconds – Hard
Requests per month: 5000 – Hard
Requests per second: 2 – Hard
I'm really worried of the 5000 requests a month. If my apps starts to be a bit popular I guess 5000 requests /months would become an issue. (500 users making 10 requests a month seems to be easy to reach)
So maybe I should start with another service instead of Sencha io, except if there is way ($$) to be sure I would be allow to exceed those limits.