Thanks to all who have taken the time to answer. I also posted this question on Quora at http://www.quora.com/Web-Development/If-a-startup-plans-to-eventually-

Thanks to all who have taken the time to answer. I also posted this question on Quora at http://www.quora.com/Web-Development/If-a-startup-plans-to-eventually-operate-on-both-web-and-mobile-what-must-it-consider-when-deciding-which-platform-to-start-on http://www.quora.com/Web-Development/If-a-startup-plans-to-e.... I should have clarified that I wasn't looking for advice for a specific startup, but rather to draft up a general guide of pros and cons to consider for any startup facing this decision. I'll absolutely take all of the comments made on this thread into consideration when I write the post!