Just noticed this in Edge Beta v100. Perhaps some A/B testing thing. Bing appends a "msclkid" unique hash to the destination URL querystring of search results (not ads or sponsored links) which can be read by the destination site for purposes of ad tracking.<p><a href="https://help.ads.microsoft.com/#apex/ads/en/60125/2" rel="nofollow">https://help.ads.microsoft.com/#apex/ads/en/60125/2</a>
This is so advertiser spending money can report back which ads worked or not. Google has the same thing it’s a gclid. Both of these are well documented features for search ads and display ads to securely communicate a conversation event back to ad platforms. Remember when you click a paid ad someone is spending money. How else would you like to see it work? Also in case you were wondering these are opt in features by the user of the ad service. Typically called auto tagging