Pretty sure that is what tailing the log during development is all about. I don't see what is so obscure about it, in the Rails based examples in the post, one can just see the logs flying by with the exact queries being executed.
It is, but a developer that's using ORMs because they're scared of SQL tends to be the same type of developer that will decide not to look at those.
I'm not dismissing ORMs - I use Sequel (the Ruby ORM) for almost all my database access. But I've also seen enough people use ORMs as an excuse to pretend they don't need to understand SQL or understand the database to understand why some people look at ORMs with suspicion.
A lot of code that is obviously bad when the database queries are plain for everyone to see are not so obviously bad when it's less clear if that method call translates to a database query or just extracts data locally.
Note that this is a general issue with this type of abstraction: It is a common complaint against transparent RPC wrappers as well that if they're too good at hiding that an object is remote it's easy for someone to carelessly cause massive amounts of unnecessary roundtrips.
I don't know, I find that a lot of the people that write the most inefficient ORM code would also not spot the inefficiencies in SQL queries either.
On the flipside, I've seen a lot of people that can write efficient SQL queries, but then turn around and ruin their performance with a bespoke code model that inefficiently calls those SQL queries and poorly leaks the memory and database connections while doing so.
A good ORM makes it rather easy to fix an inefficient query of a fellow developer or previous self (almost all of the examples in this article are effectively one-line changes; many of the biggest performance gains I've made in ORM usage have been removing code and/or making it more readable), but fixing the mistakes of a bespoke model can be a huge challenge with a lot of surprises.
It seems unlikely that this would be 100% effective though. I am pretty sure that companies like this use data from your immediate social sphere as well to make pretty relevant assumptions about you.
For instance, when I buy a product, certain others of my friends will see this same product promoted to them.
My friend once looked something up on Facebook, while we were in the movie theater (before the movie started ;)) and sure enough I was getting the ads for that same event as soon as I got home and looked at my phone.
Of course, on a more massive scale, this could theoretically work.
