I'd suggest a slight change in strategy. After 12 months, don't ask people. Just start gradually taking things away. Those that contact you to ask why it's miss

I'd suggest a slight change in strategy. After 12 months, don't ask people. Just start gradually taking things away. Those that contact you to ask why it's missing are the ones who probably find it useful. The scream test works everytime, in 80% of scenarios...