The analyzer took the impossible problem—watching billions of packets per second—and reduced it to a manageable stream of samples, then turned those samples into answers. It is the ultimate example of "a little data, well analyzed, is better than all the data, unanalyzed."
InMon made sFlow an open standard (RFC 3176, later 7452), free for any vendor to implement. Unlike Cisco's proprietary NetFlow (which required complex stateful tracking on the router), sFlow was and ran entirely in hardware on the ASIC. This was much cheaper and safer for routers. sflow analyzer