Apparel ROI is harder to measure than digital marketing but not impossible. The right metrics depend on what the program is for.

For employee programs (brand identity, culture): track retention metrics before and after implementing a quality program. Track employee survey responses on belonging and pride. Survey whether staff actually wear the gear outside of work.

For client gifts and retention programs: compare renewal rates for clients who received branded gifts vs. those who didn't. Track referral rates. Survey whether the gift was memorable.

For events: post-event brand recall surveys (did attendees remember your organization?). Social media coverage featuring the apparel. Percentage of shirts actually worn vs. left behind.

For retail/merchandise: revenue and margin per unit. Inventory turn rate. Customer repeat purchase rate.

The simple metric that works for almost any program: cost per impression. Estimate how many times the garment will be worn in public, multiply by average visibility per wear. Compare to the equivalent cost in paid media.