On the twitter Rate Limiting page(https://dev.twitter.com/docs/rate-limiting) it says
“Unauthenticated calls are permitted 150 requests per hour. Unauthenticated calls are measured against the public facing IP of the server or device making the request.”
Is that the measurement based on enduser IP address or the server IP(ip of http:xxxx.com) ? Is there a way to increase the limit may be through some paid service of Twitter ?