Views might be important to get the attention of a potential advertising partner, but once the relationship has started then keeping it going will likely be dependent on much more relevant metrics for the advertiser. And those metrics will usually be tracked on their end, rather than via YouTube. I'm referring to metrics like click-through rate, propensity to order, revenue on advertising spend, etc. Personalized referral URLs and discount codes are what allow the advertisers to connect their tracking and reporting to the originating YouTuber.