Advertising elsewhere is bought by the impression. Creator sponsorship is usually bought by the video, at a price agreed before anyone knows how the video will perform.
The risk has to sit with someone
A video's audience is not predictable in advance. The same channel can produce results that differ severalfold between consecutive uploads, for reasons neither party controls.
A fixed fee places that variance on the buyer, who pays the same whether the video reaches its usual audience or three times it. A performance rate would place it on the creator instead.
Both arrangements exist, but the fixed fee dominates because the creator's downside is unbounded. Work is done before publication, and a weak result would mean uncompensated production.
What a brand is actually buying
Purchasing a video buys placement inside content the audience chose, delivered by someone they already trust. That endorsement does not scale with view count in a simple way.
A modest audience that acts on a recommendation can be worth more than a large one that scrolls past it, which makes raw impressions a poor unit for pricing.
Sponsors therefore price against expected audience quality as much as size, which is why rates vary enormously between channels of similar reach in different subjects.
Production is a real cost either way
An integrated segment requires scripting, filming and editing regardless of outcome, and often requires approval rounds that consume more time than the segment itself.
That work is incurred before publication, so a purely performance-based fee would ask creators to fund production speculatively for a buyer who has already secured their attention.
Fixed fees also make the arrangement schedulable. A creator can commit to a month of work knowing what it pays, which is what allows the activity to be treated as income.
How performance re-enters the calculation
Results do influence price, but between deals rather than within one. A video that performs unusually well strengthens the creator's position for the next negotiation.
Many arrangements add a performance layer on top of the base fee, with tracked links or codes paying a secondary amount, which shares upside without shifting the production risk.
Why estimates are given as ranges
Creators are typically asked for expected audience before a price is agreed, and the honest answer is a range with a floor, because the floor is what the buyer is really purchasing.
Quoting a peak figure and delivering a typical one damages the relationship more than quoting conservatively, since the buyer's budget was built against the number they were given.