A page may look great on a desktop device but terrible on a mobile device but how do you make sure the mobile viewers see the mobile page which works best for them? What about showing a offer to certain countries. Did you know some countries don’t use certain payment systems? So what's the use in showing them a offer they can’t purchase.
Wastes you traffic and loses you sales as you could be sending that viewers somewhere they can purchase from. I bet you are thinking that all sounds very complicated to set up? And if you were to do it yourself using different scripts then yes it would be.
But what if there was an all in one solution that did all this and much more for you?