The Funnel Analysis chart is a powerful and popular chart in Amplitude. There are many different features in the Funnel Analysis chart and today I want to talk about a common question that we get about the differences between the Conversion funnel chart and the Conversion Over Time funnel chart: Why is the conversion rate in my Conversion chart higher than the conversion rates in my Conversion Over Time Chart?
The Conversion funnel chart (bar chart) performs a different analysis from the Conversion Over Time chart (line chart). Let’s look at this 2 Step funnel as an example:
This Conversion funnel chart shows us how many unique users performed Step 1 (Favorite Song or Video) in the last 30 days, and of those users, how many of them converted at Step 2 (performed Purchase Song or Video) within 1 day of performing Step 1 and how many of them dropped off at Step 2. Note that the Conversion chart counts unique users. This means that if a user converts multiple times within the last 30 days, the user will still only be counted once. This is why Conversion charts are great for seeing overall conversion of your users.
If you switch to a Conversion Over Time funnel chart:
Now, rather than seeing the overall conversion for your users, you get to see a breakdown of conversion per day. The percentages plotted in the Conversion Over Time chart represent conversions per unique user per interval (Day/Week/Month/Year etc). A user could be counted more than once in this Conversion Over Time chart if they performed Step 1 on multiple days within the last 30 days.
For example, let’s say User A performs Favorite Song or Video 3 times in the last 30 days and also performed Purchased Song or Video 1 time in the last 30 days:
- Jan 1 - Favorite Song or Video
- Jan 5 - Favorite Song or Video
- Jan 10 - Favorite Song or Video
- Jan 11 - Purchase Song or Video
Our chart definitions require that a user performs Step 2 within 1 day of Step 1. In this case, User A has entered the funnel 3 times in the last 30 days, but only completed the funnel once. In the Conversion funnel chart, User A is counted as converted once while in the Conversion Over Time chart, User A is counted as converted once on Jan 10 (the day the user entered the funnel) and counted as not converted twice for Jan 1 and Jan 5. User A is still counted in the denominator of the conversion percentage for Jan 1 and Jan 5, but they are not counted in the numerator of the percentage, resulting in a lower conversion rate on those days.
Because of this daily breakdown in conversion rate, the Conversion Over Time tends to return lower conversion rates while the Conversion chart tends to return a higher, overall conversion rate.