More often than not, the slowness end users experience is problems in the front end - not the database. Think uncompressed assets, cache misses, or unused javascript and stylesheets. It's very likely most pages in your application are (or should) be served entirely from cache, so end users will benefit much more from front end optimizations.
This statement is dangerously false. Unused javascript and stylesheets is where you would start your performance debugging when users complain of slowness ?
