On a high-traffic site will Clarity capture every session per variant?
Our site does well over a million sessions a month. My worry is that if Clarity does not record everything, my per-variant replay pool ends up patchy and I draw the wrong conclusion analysing behaviour that was only partially captured.
What should I expect at that volume?
2 answers
Your instinct about the volume is right, and the limit comes from Clarity, not from Croct. Clarity records up to 100k sessions per project per day and then samples beyond that. At well over a million sessions a month you will cross that threshold on busy days, so not every session gets a replay. That sampling is a property of Clarity itself and is unaffected by whether Croct is connected.
What the integration changes is only the ability to filter whatever Clarity did capture by audience, experiment, and variant. It does not raise or lower Clarity's capture ceiling.
The important part for your decision-making: Croct's own experiment analytics remain unsampled across 100 percent of the data, so your quantitative results are not affected by Clarity sampling at all. The practical pattern is to use Clarity for qualitative spot-checks per variant and Croct for the full quantitative measure.
This is noted on the Clarity integration page, and the reasoning behind unsampled experiment results is worth a read alongside it.
Can confirm from a high-traffic store. We do a few million sessions a month and Clarity is definitely sampling on peak days, but it never mattered for our conclusions. We read the win or loss off Croct's numbers, which see everything, and only dip into Clarity to watch a handful of sessions per variant to understand the behaviour. That split has worked fine for us for months.
If bot traffic is also on your mind at that volume, the thread on unsampled results and how bot filtering fits in is relevant.