Why does Google Analytics use __utm.gif?
问题 Just trying to understand why they didn't use a REST API. 回答1: In REST, clients initiate requests to servers for resources; servers process those requests and return appropriate responses. The utm.gif is not involved in server-to-client data transfer, but instead it's involved in moving data in the other direction. Of course REST has HTTP methods for the client to communicate with servers (GET and POST) and indeed, Google Analytics directs the client's browser to send all analytics data to