Is it possible to have a person a part of a SFDC campaign / Marketo program without having it automatically sync to SFDC?
Example: results from a webinar. If someone is completely brand new to our instance and attended a webinar. However, they did not meet the criteria to become a brand new lead for sales to follow up with. I would like them to be just in Marketo with that information. But if then in the future, the person becomes an MQL based on other actions. I would then like them to sync to SFDC and have that previous campaign / program information on the lead.
It is, but is will require quite some work on both Marketo and SFDC sides. and the big drawbacks is that your reporting one both sides will never be consistent.
This is not best practice, IMHO. If the lead is not MQL/SRL, I prefer to add it to SFDC but assign it to a lead queue to which sales have no access.