As the team behind a global mobile-traffic exchange, we constantly tune supply signals so you can buy installs, ROAS and brand recall with less guesswork. Google’s OpenRTB Extensions v192 (21 July 2025) drops a tiny switch — imp.ext.highengagement — that finally lets us flag interstitial and rewarded impressions designed for longer on-screen attention. This note explains what the flag really means inside our bidding pipes, how we’ve rolled it into campaign optimisation, and where you can deploy it next.
A new lever for attention-weighted buying
Our early A/B tests show ads carrying highengagement=true deliver +18% completion rate and +11% viewable seconds versus standard supply. Now you can pay for that attention without wasting budget on forced, non-viewable formats or private-deal mark-ups.
What our exchange now transmits
| Field | Location | What we populate | When you see it |
| highengagement | BidRequest.imp.ext | true for impressions where the SDK enforces longer watch-time, extra close steps or an interactive end-card | Only on mobile-app interstitial & rewarded slots after our QA bot validates UX |
We map the publisher-level engagement tags into this Boolean so DSPs and bidders can ingest the signal straight out of the box.
How we price and optimise it for you
- Dynamic CPM curve – our bidder starts 5-10 % above standard floors, then auto-discounts or boosts based on your conversion feedback loop (CPI, CPA, ROAS).
- Smart pacing – if higher engagement raises session length but dents retention, our system throttles frequency to keep churn <1%.
- Creative guardrails – brands that block extended end-cards get filtered pre-auction, so disallowed creatives never bid on highengagement supply.
Recommended playbook for growth managers
- Parse the flag – confirm your DSP ingests imp.ext.highengagement; our schema mirrors Google’s proto spec.
- Spin up a test line-item – target only highengagement=true for 7-14 days; compare CPI, ROAS and post-view retention.
- Feed us postbacks – pipe early-event revenue (Day-2) so our optimisation loop can raise bids where attention=profit.
- Adjust creative – longer watch-time supports deeper story arcs; consider 20- or 30-second rewarded videos with interactive calls to action.
What’s next on our roadmap
- Attention score multiplier – we’re prototyping a scalar (0-1) to sit alongside the Boolean, letting you fine-tune bid shading beyond yes/no.
- Engagement in Privacy Sandbox – we’re testing the flag inside Protected Audience auctions so you keep the signal as GAID sunsets.
- Exchange-wide analytics – dashboard module (Q4 2025) will break out performance deltas for high-engagement vs. baseline supply.
Conclusion
We built this exchange to give you levers, not black boxes. With highengagement, you can finally align bid price to verified attention on mobile — no PMPs, no hidden mark-ups, zero user-ID risk. Flip it on, watch the completion curve, and let us know where you need the next optimization switch
