Librarians: I'm sure it works differently in different locations, but if a book I am interested in has 78 holds on two copies, if I add myself to that long queue, will the library be more likely to purchase an additional copy? Or is the number of holds largely irrelevant? I can just wait for the queue to die down.
libraries dont hold onto this many copies of ebooks forever tho.
they have a ton as the popularity is huge, then over the months and years, start to let the copies go.
i watched that happen with a number of titles at chicago library
Britney Spears' The Woman in Me is a great example.
when i read it, i was like hold #500 on 300 copies.
now they have three copies of that book.
i would also add the chicago library has a 'purchase suggestion' link. yours may too
Kim Possible 
qurlyjoe
Anne Ominous