CRM Field Update

To conduct that functionaly, we've created a smart campaign that listens for those form fills and in the flow step updates the Lead Source field that we want to reference.  In the Change Data Value step, if you click Add Choice, you can specify, if the Lead Source field is empty, then Lead Source field is "new value".

Stephen, it sounds like what you're looking for is for Marketo to only populate if the field is blank, and not overwrite previous values. For most fields this can be controlled in the Admin section, under Field Management > Field Actions > Block Field Updates. Unfortunately Lead Source is an opportunity level field, which is not allowed to Block Field Updates.



We use multiple custom fields to manage Lead Source so that we have better control over this... Sorry this wasn't a better answer for Lead Source specifically, but hopefully you're also looking to do this with other fields!

Dory, we have created a new field in SFDC for leadsource that is separate from the opportunity leadsource.  When I chose Block Field Updates in Field Management I am presented with a lot of options.  Will chossing any of these result in the "Update Only if Blank" affect I'm looking for.

 Jonathan, your solution seems like it could work.  

Stephen, for this specific instance you'd probably want either Form Fillout, or Flow Data Change Value, depending how the leadsource is populated (hidden form field, or change data value in the flow steps). 

I like Jonathan's suggestion, but it seems to be more of a temporary fix, where you need to remember to add it each time. If this is something you'll want to protect going forward, this lessens the likelihood that someone will forget to add the "update if empty"