Amazon.com and Amazon.ca (Canada) – Sales Rank Updates Linked?

That’s so weird! Looking over recent logs since enabling every international Amazon domain for sales rank tracking, I have a built in check to make sure that sales rank was actually updated that hour. Amazon isn’t perfect, and they don’t always update sales rank information every hour. The funny thing is, whenever Amazon.com has no new updates that hour, Amazon.ca (Canada) also has no updates. These are the only two that seem to work in tandem, and also are the most frequently behind in their updates.

On any given day, Amazon.com and Amazon.ca fail to update their rankings 8 times in a 24 hour period! That’s 33% of the time where the hour is skipped! In contrast, all of Amazon’s other domains miss about 1 update in any given 24 hour period (4% of the time). Granted, Amazon.com has the largest selection and also includes the entire Kindle Edition book inventory, so there is a lot of processing to do. However, Amazon probably has a notably greater amount of resources dedicated to Amazon.com. So what’s the deal with Amazon.ca?

I’m not an expert on Amazon’s history, but my guess is that Amazon.ca was an easy extension of Amazon.com, and prior to them launching ‘across the pond’, the infrastructure was probably very closely linked together because of sheer geographical proximity. Those ties are still seen today it seems. I’m not really complaining… well, I am a little, because 33% is pretty poor, but it was interesting enough I had to mention it. Anyone else have a theory why Amazon Canada would have its core sales rank info inexorably linked to the primary Amazon.com?

Update: 3pm

Let’s be clear, a sale on .ca does not mean a sale on .com, they are completely independent of each other. The ranks move separately (the actual numbers), but when they are updated by Amazon is absolutely linked.