Call the Plain English Campaign!

"slowdown in paid click growth"

Rates don't slow -- they decrease.

Slowing is rate decreasing.

And given that in this case "growth" means rate of increase

"slowdown in paid click growth" = decrease in rate of rate of increase.

Meaningless meaningless meaningless!

Please don't confuse your less intelligent readers with this poor logic. (see "Clicks down? Imagine that!)