I agree, and I meant to emphasize more clearly that I don't think the 5% figure is meaningful (and that it shouldn't have been stated without the appropriate caveats in the article).
My main point was simply that I don't think it's prudent to create a worse experience for half of your users when you're so unlikely to gain any actionable information from it. It would be quite extraordinary if they found out that the speed increase caused a decline in conversion or a huge improvement in conversion, so I think it's safe to say that the measurement wouldn't make them reverse the change or make them allocate significantly more resources toward faster load times.
But, to reiterate, I agree that they should not have made the claim about 5% conversion when it wasn't properly supported.
My main point was simply that I don't think it's prudent to create a worse experience for half of your users when you're so unlikely to gain any actionable information from it. It would be quite extraordinary if they found out that the speed increase caused a decline in conversion or a huge improvement in conversion, so I think it's safe to say that the measurement wouldn't make them reverse the change or make them allocate significantly more resources toward faster load times.
But, to reiterate, I agree that they should not have made the claim about 5% conversion when it wasn't properly supported.