You've got some great work experience as well as strong experience outside of work (both your extracurriculars as well as your start up experience) so I think you have a good shot at these schools, especially if you can get your GMAT up. That said, you are going to want to refine your goals. Product marketing manager position at a tech firm like Microsoft is very different for from brand manager at a place like Procter & Gamble --and b-schools like to see focus. The more focused your goals are the stronger & clearer your "why MBA" argument can be. You want to think long term as well. Ultimately everything hinges on you long-term (~10 years post-MBA goal) - the ST goal is designed to prep you for that LT goal & the MBA preps you for both. In addition to WHAT you want to do, the adcom also wants to know WHY as well as your VISION for what you plan to change or accomplish in that goal. So definitely do some thinking there. But long story, short - once you firm up your goals & flesh out those details I mentioned I think you will be in a good place!