Comment by HoLyVieR

The idea is more about knowing the scale of time it takes to help compare different solution. With those number you can see that it's faster to get data in memory from a distant server than to read the same data from disk. In common application that means using disk storage is less efficient that storing it in a database on an other server, since it usually keeps almost everything in memory. It also tells a lot about why CDN are needed if you are serving client worldwide. A ping from North America to Europe will always takes 100+ ms, so having geographically distributed content is a good idea.