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You should be able to use a Tally to create a count of views per product, then use a Number (or a number of numbers attributes) to pick out the count for each value in the Tally attribute.
The Tally attribute creates an object of key:value pairs where the key would be product name or product ID, and the value could be count or value (in this case, an incremented count).
So, as customers view multiple products over time, you are recording a count for each product whenever it is viewed.
Once you have this, you can set up custom rules that test against values in the tally.