Sephora-style sample + GWP (gift-with-purchase) at PDP, doable?

Yes, and skincare conversion lift on sample selection at PDP runs 12-22%. The Sephora pattern is the gold standard. Three implementation options:

• Magento native “related products” + custom widget, for the simplest case (pick 1 free sample from a curated list). Cheapest path; ~$1.5k to build. The reco logic can pull from the customer’s quiz answers so the samples are personalised.
• Aheadworks Free Gift ($199, $399 one-time), cart-rule based GWP. Customer hits $50, picks a free 5ml deluxe sample from a list of 4. Native admin UI for marketing team.
• Custom Magento module, tiered samples ($30 spend → 1 sample, $75 → 2 samples + tote, $150 → 3 samples + tote + brush). ~$4k, $8k to build. The pattern Sephora and Ulta both use.

Inventory mechanics: samples are 0-priced SKUs with separate stock counts. Auto-deplete on order; trigger reorder cron when sample stock drops below threshold (samples run out fast and angry customers complain). Cost-of-goods on samples is real, assume $0.40, $2.50 per sample, write it into the order P&L not the marketing budget.

GWP (gift-with-purchase) trigger logic: above $X, free deluxe-size moisturizer added automatically. Show the GWP visually in cart with “your free gift unlocked” messaging, this is the conversion lever, not the gift itself.

Bonus: sample-to-full-size conversion tracking. Tag the customer with which sample they got, trigger Klaviyo “loved your sample? get the full size” flow at day-10. Converts at 8-15%.