Will "Lead Source" as a hidden field overwrite previous value?

[Rachel_Egan]

I am adding "lead source" and "lead source detail" as hidden fields on a few of our key web forms (contact us, request a demo, etc.) but I'm a bit concerned about the field behavior.

Will form fields ALWAYS overwrite existing field values? For example, if we have an existing lead that came through via a download - Acquisition Program is "XYZ Case Study", Lead Source is "Asset Download", Lead Source Detail is "XYZ Case Study" - but then they come and fill out the "Contact Us" form for some reason with the hidden Lead Source and Lead Source Detail fields, will those two fields be overwritten even though they are already filled?

If so, are there any ways to keep this from happening? I don't see how to set up any "if this" logic on hidden fields.

[Josh_Hill13 · Accepted solution]

Yes, it will do this UNLESS...

you go to Admin > Field Management and choose the field(s) you want to BLOCK from overwrites.

Once selected, go to the menus and choose Field Blocking and it will ask you which methods to not accept overwrites from. If there is a NULL value, it will be written. If there is an existing value, Marketo will reject it based on the origin.

SFDC can still overwrite the value unless you block it on either end.

[Grégoire_Miche2]

HI Josh,

SFDC is also an origin you can block updates from. In which case, Marketo will always keep the first non null value.

Weird thing, though, you can still change the values in SFDC, but then Marketo and SFDC get desynchronized. See here : Block field update from SFDC desynchronizes SFDC and Marketo

-Greg

[Rachel_Egan]

Got it - thanks for the help! I will look at these options and figure out what's the best way to handle so that it doesn't overwrite, AND doesn't de-synchronize with SFDC.