Have you ever been through the frustrating process of saving an Excel file to .csv so that you can import it into Marketo only to find that the international characters in a lead's name or address (such as letters with accent marks or Japanese characters) get converted to question marks? I just found a solution that is much easier and (so far) more reliable (yay!) than what I was doing previously.
Instead of saving the file to a (comma-delimited) .csv file, save it as a Unicode .txt file and simply import the Unicode file (see attached screenshot). If you're like me, you might at first open that Unicode file with a text editor like Notepad to check it and think - Oh, no! This won't work. My international characters are there but there are no commas. How do I turn this into a comma-delimited file? The answer is, you don't have to! Marketo accepts tab-delimited files, too (Good file-formatting accepting job, Marketo! ).
To give credit where credit is due. I found the solution here (thank you, AbleBits!):
Note that I use a PC and have not tested this on a Mac (because I don't have one).