For me it was pictures on tumblr. Someone I follow posted Magi pics from time to time.
I found the name of the Manga in the tags and started researching.XD In the beginning I was really frustrated since there wasn't even a wiki article at the time (one week or something later there was
thx for that by the way) and the Manga was up to chapter 44 when Judal just appeared.
I already have cosplay plans for Magi. ^^
@Shichiyoru: I just see a white square?