Naturally such an important and effective word as impact cannot be limited to a single use, as a noun. No, if something can have an impact, then it must be able to impact other things. Now to be fair, impact has been in use as a verb for a long time—apparently since its introduction into English in the 17th century, going by my dictionary. But the Microsoft style guidelines (as a purely non-random example) have been quite clear on the matter for at least the past seven years that impact is to be used only as a noun, not as a verb. Of course, nobody reads those guidelines anyhow, and even if they did, they certainly wouldn't let that get in the way of some impactful writing! It's crucial to impact the customer with the most impactful writing so that the sales pitch will have the desired impact.
I'm certain the problem is obvious, now. By trying so hard to impact customers all the time with impactful writing about the impact they can get from the impactive products or services they're selling, impact itself is losing its impact. So today I would like to propose that marketing writers adopt a new term into their vocabulary: kaboom. KABOOM! It's much more than just an impact—it's explosive! Think of the kaboom that customers could get by using the kaboomful products or services to kaboom their productivity issues, for example. The kaboomfulability of kaboom to bring new levels of kaboomfulness to marketing writing so that it kabooms the customer much better than impact could ever impact them should be clear. Think of all the leverage you'd get by leveraging kaboo—hey wait. Leverage. Now there's a word that's getting tired too. And really, it's kind of dry and spineless and corporate sounding, isn't it? We need a word with some sweaty oomph to show people that you really mean it when you're using something, and leverage just doesn't have that. Might I suggest… manhandling?
*Not to mention the real reason is probably that most of them don't understand the different meanings and usage of "affect" and "effect".