Solved
SFDC Lead Source - writing text into a picklist field type
I've seen this working before. Right now we are implementing Marketo and have a "change data value" on our forms to update the lead source. In Marketo we've added unique identifiers in the lead source but in testing the lead sources we defined in Marketo aren't coming through in SFDC. It's populating with one of the picklist values instead.
Any ideas on why that might be happening.
Cheers,
Richard