I think in this case it probably ends up suggesting random books that were read by your 'cluster' at different periods of their life (i.e. when they were a chil

I think in this case it probably ends up suggesting random books that were read by your 'cluster' at different periods of their life (i.e. when they were a child) that they may not necessarily like to read now (I loved this book when I was a kid: 5 stars)