Predicting on an individual basis would be more accurate, since it’s much more likely to catch edge cases and follow preference changes over time. At the same time, it’s more expensive and the price scales with the size of your customer base, unlike categorization. That’s probably why most businesses don’t practice it. Social media algorithms use both, maybe because technologies like neural networks push the price down.
Predicting on an individual basis would be more accurate, since it’s much more likely to catch edge cases and follow preference changes over time. At the same time, it’s more expensive and the price scales with the size of your customer base, unlike categorization. That’s probably why most businesses don’t practice it. Social media algorithms use both, maybe because technologies like neural networks push the price down.