When I was a kid, Emily Post said always tip 10%. In college, the buzz around campus was that 15% was what the proletariat deserved. The past decade or so, I ke

When I was a kid, Emily Post said always tip 10%. In college, the buzz around campus was that 15% was what the proletariat deserved. The past decade or so, I keep hearing you need to give 20% if you don't want to make enemies of the servers. Now, are you telling me it's become 25%?