You have relatively little space to get your message across and so ad copy needs to be well targeted, otherwise you can find yourself with a high number of clicks but not enough conversions. Whilst it is possible to change your bid strategy so that you only pay for a particular action (conversion) instead of simply just paying for clicks, it is still important to make your ad copy work hard for you.
It may be best for you to have a number of highly targeted adverts instead of a single one, this is a good strategy when you are targeting longer-tail keywords and phrases. The more specific your advert is, the more specific the landing page content needs to be.
Making use of the various additional extensions you can include in ads like site links, call-out extensions, ratings and location information is useful for customers and also helps to make your ad copy stand out on the screen.