We didn’t see this coming. Drake’s If You’re Reading This It’s Too Late (Young Money/Cash Money/Republic) will debut at #1 on the HITS Album and SPS charts next week, spoiling what looked less than 24 hours ago like a slam dunk for the Fifty Shades of Grey soundtrack—but the marketshare goes to the same place, so Republic can’t complain. What’s more, the surprise mixtape could see first-weekend sales of 500k. Strangely, as of 8am PT, the album has yet to appear on the iTunes chart. But there’s a precedent: It took Beyoncé’s 2013 surprise release several hours before landing at #1.

So will If You’re Reading This It’s Too Late be the best-selling or highest-debuting mixtape ever? Our research gnomes have come up dry in their attempts to find evidence of any mixtape exploding like this one. But is If You’re Reading This really a mixtape, or is it actually a proper album disguised as one?

As our Michelle S. points out, mixtapes usually have rappers over other people’s beats, Drake doesn’t do that here—it’s all original material from Noah 40 and Boi-1da on production. Mixtapes typically have interludes as well, but again, not in this case. So if it is an album in disguise, what’s Drake’s rationale?

For more on the buzz surrounding Drake and more, go here.