Benefits of storing first/last date action taken user property?

Hi all,

Was wondering what the potential benefits are for storing a “first/last date action taken” user property.

For example, let’s say I have a search event. Do I need to store a “first search date” and “last search date” user property? What are the benefits of explicitly storing a “first search date” and “last search date” user property?

It feels that just storing a “search submitted” event + auto-generated date is enough for me to perform some good retention analysis. Want to know what I’m missing out on though.

It feels like I’d need local storage and handle this logic in my own app. So want to know the cost/benefit tradeoff.
 

Thanks!

Dan