The gist of the argument being that, regardless of what you think about Facebook, hyper-targeted "lookalike audience" models to target ads against actually do level the playing field for small businesses who do not the resources to produce large scale ad campaigns. Highly recommended reading.
While that might be true, it does not change the fact that modern tracking practices are intrusive and anti-consumer. Frankly, I can't sympathize with any business, no matter how small, that is dependent on tracking to thrive.
For "ends justify the means" argument to work, we all have to understand and agree to what the "ends" are.
Typically, the "ends" is to "maximize aggregate utility across all actors" i.e. also often described as "the greater good". As shown by your example: "By stealing your kidneys we can give them to starving orphans."
However, when it comes to targeted advertising, the "ends" is "maximize aggregate utility for small and large capitalists". As such the example should be: "By stealing kidneys from starving orphans, we can sell them to temporarily[0] sustain capitalists". Which frankly is a very poor "ends" from my (and hopefully the majority of consumer's) perspective.
[0] Why "temporarily"?: Because the capitalist growth mindset will require more kidneys soon. Arguably, this implies there is no "ends" and therefore it might be incorrect to use any "ends justify the means" argument in this context.
The gist of the argument being that, regardless of what you think about Facebook, hyper-targeted "lookalike audience" models to target ads against actually do level the playing field for small businesses who do not the resources to produce large scale ad campaigns. Highly recommended reading.