Let's get this out of the way. Despite what we'd like to believe about shady co-op boards turning down applicants for wearing brown socks with black shoes or failure to belong to the right clubs, the vast majority of co-op rejections are due to an applicant's bottom line [source: Levy].
And don't forget that cash is king. Be realistic in your co-op hunt -- a bank's preapproval is likely to be a little stricter than you may think, and the co-op board is likely to be stricter still.
That said, more exclusive co-ops may look not only at the amount of money but also at where it comes from. While it's illegal to turn down an applicant based on occupation, the fact that most co-op boards are allowed to keep rejection reasons to themselves can make it extremely difficult to prove that a rejection is due to your job as a pop star or a personal injury lawyer, rather than a more socially appreciated job.