I'm applying to several MA programs in Middle East Studies, and in researching the programs I've noticed that most do not even expect you to have your thesis topic decided until your second year of school. As such, the idea of an "advisor" seems less critical in these programs. However, many friends of mine in graduate school have stressed that it is crucial to exchange e-mails with professors whose work interests you prior to applying to the program (but most of them are in hard sciences, not liberal arts). My statement indicates only a broad sub-field of interest (20th-century politics), but it should be enough to discern whether or not a particular program would be a fit for me.
When I have tried contacting professors, most either do not reply or seemed mildly annoyed that I'm wasting their time by sending off niceties with a clear agenda in mind. I don't have any questions to ask that I can't easily find the answer to by digging through their school's websites.
So my question is, do I really need to be blindly e-mailing professors just for the sake of having talked to them before my application came in? Is it expected like an :optional" cover letter for a job, or should I only e-mail them if I have something I need to discuss with them? How big of a difference can this make in my chances of being admitted? I already have extremely high grades and above-average test scores, plus a decent statement, while I'm not too sure about my recs and writing samples.
In some cases I have already put in my application, so that window of opportunity may have already passed. Is it advisable to contact professors in these programs anyway?