Marketing Channel first touch is a life time variable. It will hold the first value ever seen for the user. Often times people will put the same value into different evars with different expirations on them (IE, visit, one week, 30 days are the most common). This way the can run reports on the diffe...

You can used the Classifications API to import classifications: analytics: https://github.com/Adobe-Experience-Cloud/analytics-1.4-apis/blob/master/docs/classifications-api/index.md​ but unfortunately, sFTP is not currently supported for importing classifications.