But even given that Android notification SPAM would be less annoying than iOS notification SPAM seems to be, why don't I ever see sketchy Android apps even trying that? Am I just not downloading apps from the wrong places?

Why do you capitalize "spam"?

My logic was that because they're unobtrustive, they're way less likely to get clicked on, and so sketchy Android devs don't really bother with it.

AirPush was one company that did (does?) sell ads as Android push notifications. On the whole, they're really not that widely used anymore, though - partly because Android users pushed back hard against them about a year ago, IIRC, but also because the newest version or two of Android makes it really easy to identify the offending app and disable the notifications.

If I remember correctly, the pushback was before the new notification tray, so it may have been Android's own response to the problem.

It is now against the Play store developer TOS to have notifications unless they clearly identify what App it is coming from, I think this makes things like AirPush much more difficult to pull off.

You know, I'd noticed that you can easily find out what apps generate notifications but it literally had never even occurred to me that that was the reason for that addition.

There was a company for a while that was trying to do that. People exploded with anger (number one, it was hard to identify what app was the cause, number two, it was as annoying as it much be for iOS users). Almost all apps removed it, the company changed strategy if I recall and Google threatened to ban their apps.

But other than one Zynga game, I never, ever get spam notifications and that Zynga game was installed for about an hour or two.