Cost Data Upload via Google Analytic's Management API with Google Sheets

costdata.gs

function uploadData() {
    var accountId = "xxxxxxxx";
    var webPropertyId = "UA-xxxxxxxx-x";
    var customDataSourceId = "xxxxxxxx";
    var ss = SpreadsheetApp.getActiveSpreadsheet().getActiveSheet();
    var maxRows = ss.getLastRow();
    var maxColumns = ss.getLastColumn();
    var data = [];
    for (var i = 1; i <= maxRows; i++) {
        data.push(ss.getRange([i], 1, 1, maxColumns).getValues());
    }
    var newData = data.join("\n");
    var blobData = Utilities.newBlob(newData, "application/octet-stream", "GA import data");
    try {
        Logger.log(blobData.getDataAsString())
    } catch (err) {
        Logger.log(err)
    }
    try {
        var upload = Analytics.Management.Uploads.uploadData(accountId, webPropertyId, customDataSourceId, blobData);
        SpreadsheetApp.getUi().alert("Uploading: OK");
    } catch (err) {
        SpreadsheetApp.getUi().alert(err);
    }
}

Here is a full tutorial on how to use this script
In the script editor go to Resources > Advanced Google services...
Turn the Google Analytics API on
In the same overlay window click link to the Google Developers Console
In the Google Developer Console find the Google Analytics API and Enable it

Please note that Logger.log(blobData.getDataAsString()) could throw an error if you try to upload very large files.

I recommend to either remove the Logger.log, or try and catch it.

thanks for pointing out the potential error @pbkool
I've updated the code to add the try and catch