Have come across an interesting question that I can't seem to answer myself nor can I find an answer to on these forums.
I'm trying to add a subscriber with custom fields (using the AddWithCustomFields API call). It's adding the subscriber without issue with standard 'Text' custom fields, however it doesn't appear to be saving the 'multi-option' field - and I've tried everything as the 'value' in the SOAP call.
So, for example, say the custom field is 'Age Group', and it has the following options:
25 - 34 years
35 - 44 years
45 - 54 years
55 - 64 years
65 and over
I've tried to use the actual textual content of each option as the value for the custom field Key, AND also the mailbuild-assigned ID (e.g. 10999 - like you see in the 'create a subscribe form' auto generated HMTL) but no luck with either.
Ideas? Have I missed something really simple here? :)
You should be able to do what you are outlining here. I've gotten back to you via support, so we can take up the issue there, and work out exactly what is going on.