One brand's longest-running ad tells you what works for them. That could be their creative, their audience, or luck. When four competitors independently converge on the same structure, that is the category telling you something.
Step 1: Find who actually advertises
Start here rather than with a list you assembled from memory:
Who are my competitors and which of them are running ads right now?
The distinction matters. A well-known name that buys no ads teaches you nothing about paid creative.
Step 2: Track the real advertisers
Add the two or three with the most live ads. Volume is a rough proxy for budget, and a brand with budget has been forced to learn what works.
Step 3: Pull the survivors from each
For every brand:
Show me every ad that has been live over 90 days.
Ninety days is a useful threshold. It is long enough that nobody leaves a loser running by accident.
Step 4: Find what repeats across brands
This is the question that produces the actual answer:
Compare the long-running ads across these brands. What hook, format and offer structure do they share?
You are looking for convergence. When several advertisers with different creative teams and different budgets all land on the same opening move, that move is doing the work.
Step 5: Write down the formula, not the ad
The output of this exercise is a sentence, not a swipe file. Something like: in this category, the durable ads open on a specific problem, use a real person rather than a product shot, and lead with a guarantee rather than a discount.
That sentence is what you brief against. Copying a specific ad gives you one asset. Knowing the formula gives you a hundred.
FAQ
How many competitors do I need?
Three is usually enough to see convergence. One is an anecdote. Two can coincide.
What if their long-runners have nothing in common?
That is a real finding. It usually means the category rewards several different angles, which is good news: there is room to win without copying anyone.
Is 90 days the right threshold everywhere?
It is a reasonable default. In fast-moving categories with heavy seasonal creative, 45 to 60 days may be the practical ceiling. Look at the distribution before fixing a threshold.
Does a longer-running ad mean a better ad?
It means a profitable one, for that advertiser, with their margins and their audience. It is a strong signal, not a promise it will work for you.