Ads seem too good to be true?

I always wondered how some ads contain the very words I'm typing in my searches... Introducing Dynamic Keyword Insertion. Thanks Jacques.

Dynamic Keyword Insertion – The Ultimate Guide - RedFly Search Engine & Internet Marketing Bloglittle known feature called “Dynamic Keyword Insertion”. Dynamic Keyword Insertion is one of those “dirty little secrets” used by PPC marketing agencies and is the cornerstone of the millions of Internet marketing eBooks written by self proclaimed “gurus”.