advertising

The whole thing about Eduardo spending the summer trying to drum up advertising didn't really make sense.
(1) If Mark was dead against advertising for the forseeable future, why was Eduardo even still trying to find advertisers? And why was Mark OK with this?
(2) I find it hard to believe that Eduardo couldn't find any interested advertisers, given his business background, the fact that the website was blowing up and the fact that he supposedly spent 18 hours a day riding the subway for this
(3) Despite most of the movie being from Eduardo's point of view, the summer of '04 is focussed solely on Mark and Sean's exploits in Silicon Valley, and Eduardo is only shown again when he arrives at the house - none of his summer on the east is shown. It'd be interesting to be shown how or why he wasn't succeeding.