In Bento, you have three methods of uploading subscribers:
Using our integration with FlatFile you can click the "Super Fast Importing Tool" button on the top right of the Visitor Browser and use their intuitive widget to add visitors.
Using our own, custom importer which you can find underneath the Visitor Browser table, you may add thousands of visitors easily and quickly. This is the most reliable method.
You can send us the file over email to email@example.com with the subject line "Import Request". It'll be completed in 24 hours. Remember to invite us to your account.
With all imports ensure that your headers are the following (all lowercase):
"email" - used to identify visitors.
"tag" (only in Bento's custom importer) - you can add as many of these columns as you would like. Each one fires off a custom tag event on the visitor. Add as many as you want!
Anything else! All other headers will be treated as custom fields and added appropriately.