Whether it’s “hotels near me” or “nearby hotels,” people often search for the same things differently. So reaching your customers in the moments that matter can sometimes be a moving target. In fact, of the billions of searches made on Google every day, 15% of them have never been seen before. Couple that with shifting product inventory and content hidden deep within your website, people don’t always find what they’re looking for. That’s why three years ago Google introduced Dynamic Search Ads (DSA).
Original article by Google, http://adwords.blogspot.co.uk