What is msclkid?

Who adds it

Microsoft Advertising adds it to landing page URLs by default. Advertisers can switch it off in their account-level options.

What it means

The visit came from an ad served by Microsoft Advertising, on Bing or its partners. Microsoft's UET tag picks it up so conversions still count when cookies are blocked.

What to do with it

If the advertiser also has UTM auto-tagging on, the same URL carries utm_source=bing and utm_medium=cpc. Leave it in place for Microsoft conversion tracking.

How Vireo shows it

Vireo doesn't store click IDs, in the free plugin or in Pro.

In the free plugin, Vireo drops the query string from page addresses, keeping only a few WordPress ones such as p and page_id, so a tagged URL counts as the same page as the untagged one. The visit is counted under the referrer it arrived with.

See Referrers and sources in the docs.

Sources

With auto-tagging of Microsoft Click ID (MSCLKID), Microsoft Advertising will automatically add a unique click ID to the landing page URL.

Auto-tagging of Microsoft Click ID - Microsoft Advertising

Auto-tagging of MSCLKID is enabled by default.

Auto-tagging of Microsoft Click ID - Microsoft Advertising