When you upload a file to Nosto to bring your own customer data, it must respect a CSV UTF-8 - comma separated format and the maximum size per file is 25MB.
Some of the most frequently seen data formatting errors include:
The file is not comma separated but semicolon separated
You can find all information on how to correctly format your .CSV file here.
As additional resources, we recommend you to respect the following guidelines to create a CSV file from scratch: https://www.wikihow.com/Create-a-CSV-File