Recently a colleague of mine shared this article from the WSJ - Making a Temporary Stint Stick
http://online.wsj.com/article/SB10001424052748703630404575053262794157350.html?mod=rss_careers
I think the points here are very valid: prove yourself, ask for the opportunity, become indispensible. There is one scenario I've seen, however, that wasn't covered in the article--the preconceived notion somewhere in the company that you aren't the person for the job regardless of all other factors. It's not uncommon, especially for mid/senior marketing roles, for someone outside of the marketing department to have veto power over a hiring decision. So even if you prove yourself, ask for the opportunity, become indispensible, this individual doesn’t have first hand experience working with you. It’s very possible that having only seen your resume they will make a snap judgment that because six years ago you were in CPG and they are a technology firm and you could never make the leap. Sad but true--it happens.
So, along with all of the great suggestions in this article, you need to add “be a detective”. Find out the politics that surround the role, who are the influencers, who has veto power. What are their hot buttons? How can you dispel any preconceived notions of why you aren’t "the one"?