Would you rather have customers remain inactive on your database, or to Opt Out?

Some would argue it's better to know exactly where you stand with customer, others perhaps that if the customer remains contactable there's always a chance to win them back.

Considering that irrelevant communication is a waste of time and energy for both you and the customer, perhaps it's better to get an opt out, rather than disengagement - at least its a response! You've still got their contact details and can always courteously get in touch down the line.

The alternative is to keep sending them communications and hope that eventually they'll respond. I'm struggling to see the advantage of that however, but perhaps someone else has an alternative view?