Caching results for Tinyurls

Question

I was reading about tinyurls and have a question on this. If I am an API user trying to get tinyurls for a long url, would it be ok to cache the tinyruls or save it at the developers end (in this case API callers end) instead of making repeated calls? One way to think about this is it saves one explicit API call hence you can use your quota for another new API call. But I also feel that it might be ethically wrong to do so (might be wrong?). At the end of the day, tinyurls are all for saving and sharing with others, if I think from that perspective, it should be ok to cache but just wanted to know what is the right thing to do here.