Just saw this notification. You don't need to upload a list if you use the CRM integration between Marketo and AdRoll. You can simply sync an existing static list to AdRoll. I did a quick write up on how to make a static list behave like a smart list by using batch smart campaigns to keep your static list up to date: http://pages.adroll.com/rs/964-WFU-818/images/Digital%20House%20account%20re%20build.pdf
Let me know if this answers your question!