The Ecomm Analyst

Attribution windows get treated like a high-stakes modeling decision when for most stores they barely move the number that ends up driving budget. Operators will argue 7-day click versus 1-day view for an hour, then approve spend off raw platform ROAS without a second thought. The window matters, just not in the way the argument usually assumes, and once you see what it actually controls you can stop losing sleep over it.

When I want to know how much a window is really doing on a given store, I run the same orders through ThoughtMetric on two different windows and compare the totals side by side. A disclosure before I keep naming it: I work with ThoughtMetric, so I have a commercial interest in the tool. Factor that in. The reason I run the test is that nine times out of ten the revenue that shifts between a 7-day and a 1-day click window is small against the decisions people hang on it.

What the window actually decides

An attribution window is the amount of time after an ad interaction during which a later purchase still gets credited to that ad. A 7-day click window says that if someone clicked your Meta ad on Monday and bought on Saturday, Meta gets the sale. A 1-day view window says that if someone saw the ad without clicking and bought within a day, it still counts. That is the whole mechanic. Everything past that is an argument about how generous you want to be with the word caused.

Why 7-day click is a sane default

Most DTC purchases happen within a few days of the click that actually mattered. A longer window mostly lets the platform reach back and grab credit for sales it had little to do with, and a shorter one cuts off legitimate retargeting conversions that land a day or two later. The 7-day click, 1-day view combination is the common standard for a reason. It is roughly aligned with how people actually buy a sub-$200 product, and it is stable enough to compare month over month. If your considered-purchase cycle is genuinely longer, say a $600 mattress that people sleep on for two weeks before buying, then a longer click window is defensible. Pick it on the basis of your real purchase cycle, not on which number looks best.

Where view-through gets you in trouble

View-through is the setting that quietly inflates everything. Counting a sale because someone scrolled past your ad without clicking is the most generous possible reading of influence, and the platforms love it because it makes campaigns look better than they are. On a prospecting campaign with huge impression volume, view-through can double the reported conversions without a single extra dollar of real revenue. If you ever compare two tools or two windows and one of them is dramatically rosier, view-through credit is usually the reason. When I am judging whether a prospecting channel is pulling its weight, I turn view-through off entirely or report it in its own column so it cannot contaminate the click-based view.

How I actually set it

• Pick one window and hold it constant across every channel and every report, so the numbers are actually comparable. The 7-day click, 1-day view default is fine for most stores under $20M.
• Turn view-through off, or at minimum report it separately, whenever you are deciding if prospecting is working.
• Match the window loosely to your real buying cycle. A $40 impulse product does not need 28 days of lookback. A high-consideration purchase might.
• Then stop changing it. The window you can track consistently for a year beats the theoretically perfect window you reset every quarter and can never compare against itself.

The window is a measurement convention, not a truth setting. Pick a reasonable one, keep it stable, and put the energy you saved into the question that actually moves money, which is whether the channel is driving incremental sales at all. That question is worth a hard look. The difference between a 7-day and a 1-day window almost never is.