Take a look at this SEOMoz blog post about EMD's and especially the list starting at the paragraph "A few things to consider for solving problems with EMD sites".
EMD is just one of more than 100 factors search engines take into account when ranking your page[s].
Of course you have to provide great content. Do you want to find crap? Do you offer content that is unique, useful, shareable, of great quality, written for visitors (not the SE), do your visitors like the content or bounce immediately? Do you have a well established brand? Own some authority over years? Links from authorities? Are you in a network of trust and linked from within the social web? Do people trust your content? No grammar and spelling mistakes? Would people leave their credit card number in a payment process on your site? Does the content describe a topic well? Would you bookmark the pages? How much ads are on the pages? Are certain elements overoptimized (link anchor texts etc.)? Do you link to sites that are spammy or de-listed? Do you have duplicate content issues?