When you write an ad, you should be writing it for your specific target demographic. There is one large issue with that, though. You miss out on hitting those targets.
Your banner ad on a specific traffic source may find a majority of that traffic converts well, however, maybe the other 50% seeing your ad aren’t connecting and thus not clicking or converting. This is a simple problem that can be solved with multiple ads serviced through one ad.
I borrow the Facebook ads format to do this, and that makes it quite simple. Go take a look at them, and you’ll see it is quite easy to fit 2 – 3 of these style of ads into one 300 x 250 ad, or any size banner you are going for.
This allows me to take multiple unique angles and images and stack them together. If a viewer doesn’t like the first message or image, maybe the second or third will take their interest.