Estimation question

How many webcams were sold in the US during 2020?

Practice this question out loud. An AI interviewer asks it, follows up like a real interviewer would, and scores your answer. Type or speak.

What this question tests

Tests structured estimation, market-sizing, using reasonable population and adoption assumptions that are explicitly marked.

Frame webcam sales as buyers in 2020 times units per buyer, driven heavily by the pandemic's work-from-home and school shift.
Assume US population around 330M, with a working and studying population needing a webcam of roughly 150M, given many laptops lack a decent built-in camera.
Assume 15-20% of that 150M actually bought a webcam in 2020 due to the sudden demand spike, roughly 25M buyers, mostly buying one unit each.
Adjust downward for the well-reported 2020 supply shortage, since demand outstripped supply for months.
State a final estimate of roughly 15-25M webcams sold in the US in 2020, clearly labeled as assumption-based.

Labels every number as an assumption clearly, rather than presenting a false-precision figure.
Incorporates the real 2020 context, widely reported webcam shortages, to sanity-check the estimate downward.
Uses a clear top-down formula that an interviewer could follow and challenge.

Giving a bottom-up guess with no stated assumptions at all.
Ignoring the well-known 2020 supply shortage as a sanity check on the final number.

How would you sanity-check this estimate against real sales data if you had access to it?
How would laptop built-in camera penetration change your assumption?