It would be wonderful to keep the service free, but it's also a fair point that the data usage must be tremendous. Perhaps a balance could be achieved by rate

It would be wonderful to keep the service free, but it's also a fair point that the data usage must be tremendous. Perhaps a balance could be achieved by rate limiting by IP to encourage caching by devs. I'm guessing a fair amount of waste occurs from CI testing. Normally once an end user has the image that should be enough.