As Consequence of Sound notes, this is not only Weird Al's first No. 1 ever, but the first comedy album to debut No. 1 in 54 (!) years (which is double awesome).
According to Billboard, Yankovic's 14th LP moved 104,700 copies in its first week. The success is largely attributed to the viral success of those eight aforementioned videos, which received more than 20 million cumulative views during their initial week of release. Yankovic's label, RCA, refused to pay for the videos, so instead the comedian partnered with sites such as Funny or Die, College Humor and Nerdist to help bring his project to fruition (RCA must be sorry for that now, for sure).
Yankovic has two previously top 10 albums in 2006's "Straight Outta Lynwood" and 2011's "Alpocalypse." His previous best sales week was back in 1991, when "Straight Outta Lynwood" sold 73,000 copies in its first week.