I don't understand the Amazon.ca shipping protocol.

I had 4 books on order for the last couple weeks. They couldn't ship them all right away because a couple of them were taking longer than just 24 hours to ship. No problem.

So on Tuesday I got 3 of the 4 books. Ok. The last one will ship sometime in a couple weeks. No biggie.

They shipped the next one and I got it on Wednesday.

WHY!?!

Oh well. At least I have them all and didn't pay any shipping on any of the packages.