True, Jason. But giant advances these days are reserved for brand-name authors. Mid-listers and new authors are often offered very, very small advances. Minnow publishers -- like my own house -- offer no advance but a slightly higher royalty.
A funny thing with royalty advances, though, is that folks think these actually ARE 'payment in advance'. In reality they ain't. They are payment for raw materials that may have taken the creator several years to produce. They are actually payment in retrospect. Can you think of any other industry that calls payment for its raw materials an 'advance'?