Why offline channels are structurally harder
Every method covered on web attribution and mobile attribution depends on a click, an impression log, or an app install event to anchor the credit to. TV, podcast, in-store, and phone-call conversions have no equivalent default event - each channel needs a purpose-built proxy before it can be measured at all.
Call attribution
Call attribution uses dynamic number insertion (DNI): each visitor or campaign segment sees a different tracking phone number, and the call platform logs which number was dialed to attribute the call back to its source. Without DNI, a phone call is invisible to attribution entirely - it looks like a customer who "just called," with no marketing touch behind it.
TV attribution
TV attribution typically relies on matchback analysis (correlating a spike in website traffic or conversions with the exact air time of a spot) or geo-lift testing (comparing conversion rates in markets where the ad ran against markets where it didn't). Neither is as precise as digital click tracking - both are statistical inference, not a direct log.
Podcast attribution
Podcast ads are typically attributed through promo codes, dedicated landing page URLs unique to the show, or (less reliably) self-reported "how did you hear about us" surveys. There is no pixel-based method - podcast players do not expose a tracking hook the way a web page does.
In-store, affiliate, and influencer, briefly
In-store attribution typically bridges through a loyalty program ID, a coupon code, or point-of-sale integration. Affiliate attribution runs through the affiliate network's own click-and-cookie or postback tracking. Influencer attribution most often uses unique discount codes or dedicated landing pages per influencer - the same proxy-code pattern as podcast.
| Channel | Typical proxy | Main limitation |
|---|---|---|
| Call | Dynamic number insertion | Requires enough call volume per segment to assign a distinct number pool. |
| TV | Matchback / geo-lift | Statistical inference, not a per-conversion log. |
| Podcast | Promo code / dedicated URL | Depends on listener remembering or bothering to use the code. |
| In-store | Loyalty ID / coupon / POS integration | Requires POS or loyalty system integration to close the loop. |