With most website design projects we can forecast whether we can deliver the results requested. So, yes after 20+ years we pretty much can guarantee results.
In some cases we even guarantee a level of money back offer, as we are happy to share any perceived risk – beat that!  And nobody has ever asked for money back 
However we do not take on just any project, we select the ones where we know we can add value. We focus on Professional services, mainly in Financial, Legal and Construction.
And we avoid Hospitality and eCommerce, due to the crazy competition that is usually a race to the bottom.