Short answer
An impression counts as viewable under the MRC and IAB standard when at least 50% of the ad is on screen for one continuous second, or two seconds for video; large ads of 242,500 pixels or more need 30%. Viewable is the minimum, not proof anyone looked. For B2B display, buy on viewable impressions where you can, compare channels on vCPM, and add inclusion lists so the impressions land on sites your buyers read.
The standard
| Format | Share of the ad in view | For at least |
|---|---|---|
| Display | 50% of pixels | 1 continuous second |
| Large display (242,500 pixels or more, e.g. 970 × 250) | 30% | 1 continuous second |
| Video | 50% | 2 consecutive seconds of play |
The Media Rating Council and IAB set the standard in 2014; Google's Active View uses the same thresholds.
Price what can be seen
A CPM pays for served impressions; a vCPM pays for viewable ones. Divide CPM by the viewable rate to compare: $6 at 40% viewable is $15 per thousand viewable impressions, more than $11 at 80% viewable ($13.75). Google Ads lets you bid on viewable CPM directly, so you pay only for impressions that can be seen.
| Offer (illustrative) | CPM | Viewable rate | vCPM |
|---|---|---|---|
| Cheap open auction | $6.00 | 40% | $15.00 |
| Curated B2B publisher deal | $11.00 | 80% | $13.75 |
Viewable isn't viewed
One second at half size is a low bar. Ads can meet it on pages nobody reads. The ANA's 2023 transparency study found the average campaign ran on about 44,000 websites, and that made-for-advertising sites took 21% of impressions. For B2B, where the buyer is a tiny share of any site's audience, where the ad ran matters as much as whether it was viewable.
Buying rules for B2B display
- Set a viewability condition or buy on vCPM where the platform allows it.
- Use an inclusion list of sites and apps your buyers use, rather than only blocking bad ones. Brand safety for B2B programmatic.
- Prefer deals with known publishers for the core of the budget. Deal types explained.
- Judge by account engagement, not by clicks or viewability alone.
Questions
What is the MRC viewability standard?
At least 50% of the ad's pixels in view for one continuous second for display, and two consecutive seconds for video. Large display ads of 242,500 pixels or more need 30% in view.
What is vCPM?
Cost per thousand viewable impressions. Google Ads lets you bid on viewable CPM, so you pay only when an ad can be seen.
What viewability rate should B2B display aim for?
Set it as a buying condition in your DSP and judge vendors on vCPM. A very high rate on cheap inventory can still mean low attention.
Does viewability matter for LinkedIn?
Less as a buying lever, because you buy inside one feed. It matters most for open-web programmatic, where placements vary widely.
Facts checked against the sources below on 19 October 2026. Ad platforms change quickly: if something here no longer matches what you see, tell us and we will update it.
