Why did Unity Software stock plunge today? Weak guidance crushes stock

$Unity Software(U.US)$ stock plunged on Wednesday after the video game development software company said its first-quarter results were weaker than anticipated and said the rest of the year would be weak, largely due to a major impact from its ad monetization tool, Unity Ads.
Credit Suisse analyst Stephen Ju, who rates Unity (U) outperform, lowered the per-share price target to $137 from $160, noting that a $110 million impact on Unity Ads caused the weak guidance, due to reduced targeting efficacy.
U expects sales to be within a range of $1.35 billion and $1.425 billion, compared to estimates of $1.49 billion, implying revenue will grow between 22% and 28% year-over-year.