To motivate a click, marketers need to make a compelling offer and provide an urgent call to action. This is not news.
But in the particular case of search engine advertising, like Google AdWords, it’s a bit more complicated, because marketers are paying for each click. Unqualified clicks diminish ROI and can be a real constraint for b-to-b marketers, whose target audience is often very narrow.
The other constraint found in search advertising is in the copy. There are only 130 characters, spread over four lines of type, to play with. So the offer needs to be simple and easy to explain. And the call to action must be extremely concise.
Source:: AdAge – Digital