GlossaryDigital
Loop
Also called Loop lengthRotationShare of voiceSOV
A loop is the full repeating sequence of advertising slots on a digital screen: every advertiser plays once per loop, so the loop length divided by your slot duration is your share of the screen, and the loop length divided into the operating hours is how often you appear.
In more detail
The loop is the single most important number in a DOOH buy and the one most likely to be missing from the proposal. If a screen runs a sixty-second loop and your spot is ten seconds, you hold a sixth of that screen and you play once a minute. If the same screen runs a three-minute loop, the identical ten-second spot is a eighteenth of the screen and plays a third as often — for a price that may not have moved at all.
Share of voice, usually written SOV, is the same idea expressed as a proportion: your slot duration as a percentage of the loop. It is a useful shorthand as long as it is paired with the loop length, because SOV alone does not tell you how often you appear. Ten per cent of a one-minute loop and ten per cent of a five-minute loop are the same share and completely different campaigns.
Loops are also not always fixed. Some operators lengthen the loop as they sell more advertisers into it, which quietly dilutes everybody already on the screen. That is why the loop length belongs in the contract as a maximum rather than in the proposal as a description.
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How do I calculate how often my ad plays?
Divide the operating hours by the loop length. A sixty-second loop running fourteen hours a day gives eight hundred and forty plays a day; a hundred-and-eighty-second loop over the same fourteen hours gives two hundred and eighty. Same screen, same hours, a third of the exposure.
Then check that the operating hours are real. A screen quoted as running eighteen hours that is dark from midnight, or dimmed to the point of illegibility in direct afternoon sun, is not delivering the hours in the arithmetic.
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What is share of voice in DOOH?
Your slot duration as a proportion of the total loop. A ten-second spot in a hundred-second loop is ten per cent share of voice.
It is only half the information. Share of voice tells you how much of the screen is yours; loop length tells you how often that share comes round. Always ask for both, and get the loop length written as a cap so it cannot be extended under you mid-campaign.
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Why is the loop missing from most DOOH proposals?
Because it is the number that makes two screens comparable, and comparability is not always in the seller's interest. A proposal listing a location, a screen size and a monthly rate looks complete and tells you nothing about how much exposure you are buying.
Asking for it costs nothing and changes the conversation immediately. If an operator will not put loop length and slot duration in writing, that is itself the answer.
Where it earns its place
- Comparing two DOOH proposals — it is the only way to make the rates mean the same thing.
- Negotiating, because a capped loop length is often easier to win than a lower rate.
- Planning frequency, since plays per day follows directly from loop length and operating hours.
- Reconciling play-out logs at the end of a campaign against what was contracted at the start.
And where it does not
Loop arithmetic tells you how often your ad appears and nothing about whether anybody saw it. A screen with an excellent loop in a location nobody looks at is still a bad buy, and a screen that is dim in daylight delivers less than its plays imply. Treat the loop as the floor of the analysis rather than the whole of it — it makes proposals comparable, it does not make a bad position good.
Questions we are actually asked
Loop, in practice.
What is a good loop length for DOOH in India?
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Shorter is better for the advertiser, and anything beyond about two minutes should prompt a question about how many advertisers are sharing the screen. But the number matters less than the contract: the point is to have the loop length written as a maximum so it cannot be extended once you are on the screen.
Can the operator change the loop after I book?
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Some do, by selling additional advertisers into the same screen, which dilutes everyone already on it. This is why we contract loop length as a cap rather than accepting it as a description in a proposal.
Is share of voice the same as loop length?
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No. Share of voice is how much of the screen is yours; loop length is how often that share comes round. Ten per cent of a one-minute loop and ten per cent of a five-minute loop are the same share and very different campaigns. You need both numbers.
Read next
- DOOH
DOOH — digital out-of-home — is outdoor advertising displayed on electronic screens rather than printed material, sold as slots of time inside a rotating loop that several advertisers share, rather than as sole occupancy of a panel for a month.
- Monitoring Photographs
Monitoring photographs are dated, geotagged photographs of each booked position, taken at mounting and again during the campaign, that evidence the advertisement was actually displayed at the site contracted for the period contracted.
- Hoarding
A hoarding is the Indian term for a large-format outdoor advertising panel — a printed or digital display mounted on a fixed structure beside a road, on a rooftop or on a boundary wall, sold for a defined period rather than by the number of people who pass it.
Where this has a local particularity
Municipal rules, authorities and even the vocabulary change at a corporation boundary. These markets carry something specific about loop.
Knowing the word is not the same as buying it well.
Tell us the market and the objective. We will tell you plainly whether this format is the right instrument for it.