I don't believe I'd end up dossing the service as I would be querying the API in the same way their own website and mobile app do.
Considering also I expect my service to be used lightly, my traffic would probably be minimal compared to the their regular one.
But in any case I was thinking about caching/grouping the request to optimize that.
I dont know how the API works or what's behind it, so sometimes like others have pointed out, repeated polling of an api, could be causing a DOS situation and I just mentioned how the TCP Keep Alive could help with an API that could push data.
