Ask YC: Is a particular methodology of customer service advocated at YC?

I've noticed that a number of YC funded startups are known for their fanatical customer service/support. ( Posterous, Wufoo ...) PG also has the issue as #24 for startups he would like to fund:

http://ycombinator.com/ideas.html

Is there some institutional knowledge or methodology that YC has that is specifically useful for web startups?

Does anybody else have good systems that ensure quality customer service?