What Is “Share of Attention,” and Why Does It Matter for Pharma Brands?

A physician deciding between two treatments in the same indication rarely consults a single source. In one research session, they might move through a journal article, a manufacturer's product page, a congress recap, and increasingly, a medical AI platform like OpenEvidence.
Share of Attention measures how that research time splits across competing brands, the percentage of a physician's total research time spent on a given brand versus its competitors. It's a leading indicator: physicians spend research time on the brands they're actively considering, and that attention shifts before revenue does.
Does Reaching an HCP Through More Channels Increase Brand Attention?
Yes, and the effect is larger than most media plans account for. Using ZoomRx's Digital Tracker - a passive panel that observes real HCP browsing rather than modeling it from spend - we analyzed roughly 600 oncologists and NP/PAs across six indications (NSCLC, breast, prostate, multiple myeloma, RCC, and CLL) over 12 months.
Physicians reached through a single promotional channel (display ads, email, or sponsored search) gave a brand about 2.8% of their research attention. Physicians reached through two or more channels gave that brand 6.7%+ — more than double.
The lift held independently in all six indications, and every multi-channel combination outperformed every single-channel approach.
Why Doesn't Adding Frequency on One Channel Work as Well?
Because breadth and volume are different levers. Holding total touch volume roughly constant, adding frequency on a single channel produced flat-to-negative returns — Share of Attention declined as single-channel volume rose (10.8% down to 1.8% across volume quartiles).
Multi-channel exposure held a higher floor at every volume level tested. A likely cause is wear-out: the fifth email or the tenth banner impression carries less weight than the first.
What This Means for Your Pharma HCP Marketing Media Mix
If a brand's Share of Attention is underperforming, the fix usually isn't more spend on the channel already running — it's reallocating a portion of that volume into a second or third channel reaching the same physicians. Digital Tracker measures this at the individual-HCP level, so brand teams can see their own channel overlap, not just channel-by-channel performance in isolation.
The full data set — indication-by-indication breakdowns, channel-combination performance, and methodology — is available now in our report, "Channel overlap outperforms channel volume in Pharma Marketing".
Frequently Asked Questions
What counts as a “channel” in this analysis?
Three promotional channels: display advertising, email, and sponsored search. A physician-brand pairing counted as “multi-channel” when touches from two or more arrived within the 12-month study window.
How much data supports this finding?
ZoomRx's Digital Tracker panel of roughly 600 US oncologists and NP/PAs, 40+ browsing sessions each, across six oncology indications and 12 months of passively observed web behavior.
Does this mean I should stop investing in my best-performing single channel?
No. The finding is about reallocating incremental volume, not abandoning a channel that's working - adding a second or third channel to reach the same physicians outperforms adding more frequency to one.