Hi, I am new to Amplitude Analytics.
We want to track the unique product page views of each user on our e-commerce marketplace app.
So we use a user property that will +1 every time the user opens a product detail page (when the “View Product” event is triggered).
But this number goes up as a user opens the same product page for several times, which is not what we want.
How can we solve this issue? 
If you want to stick to the data schema you are currently using, this sounds like something you need to solve on the app side, not in Amplitude. For example, you could store the IDs of the viewed pages locally and update the user property accordingly.
Alternative approaches depends on what you are looking to do with this data. For example, you could create your event like this:
Then you would be able to create cohorts based on the event and “distinct values of property” (you find this option by clicking on “count” after selecting your event while creating a cohort).
Hello
Thank you for your advice.
We now store all the product IDs viewed locally, and +1 every time a new product ID is logged.
It’s not 100% perfect, but it’s definitely better!
Then you would be able to create cohorts based on the event and “distinct values of property” (you find this option by clicking on “count” after selecting your event while creating a cohort).
Are there any limits to the amount of “distinct values” a property can support?
If we are going to use them for IDs, this could mean thousands (or millions) of them. Want to know if we should design our event tagging architecture around any tooling constraints around this.
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