In at least the web development field, web servers are everywhere but are backed by very few database servers. As web servers get hit with requests they execute large queries on the database, putting the server under heavy load. While web servers are very easy to scale, db servers are much harder (at least from what I know), making them a precious resource.
One way I've heard from some answers here to take load off the database is to offload the work to the web server. Easy, until you realize that now you've got a ton of traffic internally as a web server tries to run SELECT TOP 3000 (presumably to crunch the results on its own), which still slows things down.
What are other ways to take load off the database?