“Uniques” is a count of unique users. But a unique user for you could be different to a unique user for someone else, it completely depends on your setup (particularly on whether you’re passing in your own “user IDs”). Sounds like you may have already found it, but just in case, have a read of this: https://help.amplitude.com/hc/en-us/articles/115003135607-Track-unique-users-in-Amplitude. The examples at the bottom are particularly useful to help get your head around the concept!

Regarding whether you should measure uniques or total events….no right or wrong here, that completely depends on what the business question is that you’re addressing.

Hi @recshop 

From a funnel perspective, using UNIQUE will only count the user once i.e. if the user has entered the funnel multiple times in your selected time frame, then they would be included only once in the calculation ( earliest and longest conversion ).

If you are using TOTALS, then every instance that a user enters your funnel will be counted.

So for your use case,  the conversion question you could be asking is  - Am I interested in funnel conversion for anytime a user attempts to make a purchase ( maybe Add Cart → Purchase ) or if I want to understand the overall conversion on every Add Cart event that has occurred in the time frame.

As you mentioned, if a customer bought the same product several times only the first conversion will be used for uniques. Another way of understanding this is to use the TOTALS conversion metric and then use the broken down by clause on product category to see what type of products have the highest conversion rate.

Hope this helps.

Thanks both @dangrainger and @Saish Redkar for jumping in. Super helpful! 

UPDATE: when you use Event Totals it sums up correctly. When you use Uniques it does not sum up correctly.

This may be related to this question, we’re noticing our data tables in Amplitude do not total correctly. i.e. what’s showing here is only 50% of our channels and the sum of each channel totals 170,000 yet Amplitude totals it at 150,021. I read it’s due to caching but this is not a good user experience. We’re concerned that this is misleading and does not fill us with confidence. ie, do we need to sum up the totals to be confident in the number shown each time?

Any insight here is appreciated, thanks

@mkoiva you’ve got “Uniques” as your counting method for Any Event in that table column. It’s perfectly possibly that one unique can have more than one channel, so you shouldn’t be adding the rows...the grand total at the top de-duplicates uniques that appear in more than row.

Thanks Dan, also the Total Events add up but Uniques do not and this is why. We are focusing on Uniques to see net activity changes  but can total manual charts for Senior Leadership so it makes sense to them.

We’re figuring out these nuances of how we need to report differently so thanks for your assistance.

@mkoiva I have faced a similar problem. As far as I remember, Amplitude is used to calculate Unique events according to the same principle as Totals. It means if we calculate an event with “grouping by” and without we want to see the same sum even with Unique measurement.