This trick is used all the time. In my previous SaaS company we used to write case studies to show the impact caused by our product on the business' bottomline. A typical impact used to be like conversion increased from 10% to 12%. However, this impact used to seem very tiny and absolutely not case study worthy.

Hence, we would deliberately calculate impact by taking not the previous sales but the previous conversion rate as the denominator. Thus, would 10 to 12% growth would go like "we increased Y's conversion rate by 20%."

Can't be mathematically disputed and totally clickbaity at the same time.

In that case, it’s not particularly misleading. All else equal, I’d expect an increase of 20% of sales, not an increase of 2%. Sure, a clarifying footnote/endnote would be nice.