MSCLKID is Microsoft Click ID, a click identifier used to connect Microsoft ad clicks with later website actions or conversions.
It matters because Microsoft Advertising can reach valuable search and professional audiences that are often overlooked. Clear measurement and audience structure help the channel complement Google Ads rather than simply duplicate it.
Example
Example: When auto-tagging is enabled, MSCLKID can help connect a Microsoft ad click to a later website conversion or imported CRM event.