How do you like to set up your Tags?

Given that tags seems to be a system to track program-level metrics based on flexible categories - most widely used is tracking program status for campaigns. For sources, we see examples of having dedicated source-specific SFDC campaigns to attribute success and pushing qualified leads in Marketo via choices towards SFDC (UTM is xyz, then add to SFDC-xyz, and so on) - one example could be having this sync enabled on program level and matching the source(Defined by channel) to SFDC campaigns - with pros/cons.

Triggering follow up processing based on program status change can sometimes accomodate a complete set of leads including the connected apps (if we have integrations, and statuses also map to the parties integrated)

Have rarely came across unique cases beyond the out-of-box scope, but looking for more ideas! Though UTMs and source tracking is more relevant since these are usually based of delivery techniques.

Let's first say that you don't want Marketo Tags, which are a superset of Marketo Channel Types.

You want UTM params to do channel-offer tracking for attribution.

You searched for channel offer - Marketing Rockstar Guides 

I can't find the exact link but there are attribution suggestions there.

A Marketing Attribution Model that Works for Marketing Automation | Perkuto