How to accurately assign language tags to a large list (15k)

Hey @GVaughan,

I think you’re on the right track! Especially the use of a popup form with checkboxes asking your subscribers. 

For customers who enter your list via accepts marketing through a purchase or from a website footer form, the easiest way in my opinion would be to to ask them their language preference through the Welcome Series flow. This would be a great use case for using buttons/links to update user profile properties. 

You could even pair this function with a show/hide block if users from those two sources were being added to the same lists as your signup forms. This way all customers will be receiving the same experience, but only those who do not already have a language preference will see the option to share their language preference. Along the same train of thought, you could also even use condition splits in your Welcome Series flow to a serve a different experience for customers who have not shared their language preferences. 

Some of the strategies I’ve mentioned above are also discussed in some of the Community posts I’ve included below that I think may be helpful to review:

I hope this helps!

David