Does the company you work for (or own) retain data on customers? Odds are pretty high that it does, at least in some form (often fairly extensively). It’s often attractive to do so for both marketing and functionality purposes.
But here’s the thing, storing that data is probably a bad business decision. One that could cost your business a huge amount of money and, even worse, potential loss of trust by your most valuable customers.
Just from the IT infrastructure point of view: As your business grows and the amount of data you store on each customer slowly expands (it always does), your cost for storing that data also grows. Rather quickly. Even if your data center is already well equipped, this is a not-insignificant recurring expense (failing drives, energy costs, other equipment needs, etc.).
Source: NW Security 1