We're talking about two different things here - I'm talking about music, you're talking about business.
"Get Lucky" is the most overhyped record of the last God knows how many years. It sold a lot, but it's not a good song. Far from it. "Blurred Lines" isn't even worth discussing. "Happy" is by an overhyped performer, whose hype is directly related to at least one other overhyped record and was produced as part of the soundtrack to an overhyped film. It doesn't read well, and if you can see comparisons to Motown, other than by measuring success, you need to get your ears cleaned out!
You really honestly think Pharrell fans are going to become serious collectors and train-spotters in the future? Obviously one or two will, but that's despite liking "Happy" not as a result of it. It'll be a load of people's ring tone for a couple of weeks before becoming the tune that gets your granny up on the floor at a wedding.