Entry Event

An entry event is the event that admits a user into a funnel, forming the base population against which all later rates are measured.

The entry event is the denominator of the overall conversion rate, so choosing it directly decides whether the funnel rate looks large or small. Set the entry event too broadly, say any pageview, and the denominator inflates and the rate looks artificially low; set it too narrowly and part of the real users fall out of the analysis. In a closed funnel the entry event is necessarily the first step and someone who did not do it never enters; in an open funnel a user can enter from a middle step, which complicates the definition. The key point is to choose the entry event to fit the question: for measuring onboarding it is “first signup,” for measuring purchase it is “first product view,” and carelessly swapping the two builds two entirely different funnels.