Would IoT change "Spray AND Pray" to "Spray OR Pray" scenario?

Contextualising the solution or service for the right set of customers is the biggest challenge of any business. 
Jokes like, "Spray and Pray" are very common in marketing community.
A few month ago, there was a session on "Social Media Marketing" at IIM Bangalore, and apart from all the data, and tips that the speaker had spoken about, he also shared the joke - 
"Only 50% of or marketing efforts are materialised, the only difficulty is that you don't know which 50%." 
We may laugh, or feel light and slightly overcome the stress of having failed in launching certain campaigns etc., but the question that we really need to figure out is - How do we know our customers?
And it's not as simple as having KYC (Know Your Customer) information, as banks maintain periodically. We really need to know who the person is, his past and present, his connections (means how he is placed in this world or people, devices and apps), his activities, and understand how it all impacts on him, and then also how and who all are trying to approach him at that particular moment, and then predict his needs, decide if my product/service can fulfil them, and then offering a helping hand - in right manner FOR him - or her. 
Its complex, as we really don't have a real view or understanding of all associated parameters, and their as resulted impact.
With the recent rise and possibility of having a connected world (Devices and Data, in Internet of Things), the challenge of having information could be easily overcome.
However, the challenge of understanding the resulted impact is still dependent on having the right tool or algorithm in place.
How much of it can be done by having a 'black-box' type algorithm? And how much of it can be coded/defined by humans who themselves can't articulate how they identify a scene, or sound, or intuition? 
Its challenging, and it is equally exciting to see how we work to overcome that challenge. Can we really break it, or would it always remain probabilistic? I see people speaking on both sides or possibilities. 
How that world would be when things would be seamlessly, and soothingly connected for humans? 
Right now, we can talk big, try to do big, think big - as thats the initial step - but we really have miles to go, before we sleep :)

PS: The image (above) made me think of writing this post. Recently, after some app updation, every-time I login to my Mac, I start seeing all b'day notifications, and I am forced to wait for a few seconds before I proceed. Many-times, I'm in hurry, and I'd not want it. So at the end, I had to spend a few min to figure out and change related settings to get rid of the mentioned situation. 
The mind argued, if we talk about that personalisation, how come I still have to perform these steps manually? Can't my laptop figure out who I'm? What I do and what's my context of that time, based on the data it stores about me? 
Can't these notifications be more targeted?
Now, I need next set of notification-spam-filtering algorithms for me (or each one of us). 
There is no end to ideas and wish-lists, but as I already said, "Miles to go .." :)