Wealth and gambling with books or streaming shows

When I look at a picture of library shelves or think of the movies and shows available when we "stream", I think of great wealth.  Not of money but of thrills, understandings, mental adventures.  But I tend to forget about the gambling part.  Yes, the library has many fine books but some of them aren't.  I face a gamble when I pick something to read or watch.  My choice may turn out to be wonderful, memorable but it may also be a dud.  I realize that I can try again but I am hoping very much that my choice will be a good one.