I will very briefly explain the abridged version of "Quantum Immortality" but you might want to read more about it.

The short version of Quantum Immortality:

"Imagine you are the cat in the Schrödinger experiment, if the many worlds interpretation of quantum mechanics is correct (a big 'if'), you will only detect a world where you are alive. since you cant notice a world where you are dead, so from the point of view of you the cat, the probability of survival is always 100%"

Simple Quantum Immortality Hacking:

This notion begs to be exploited, consider the case of wiring a random quantum experiment that would bet on a stock 50% of the times and against it for the other 50% of the times while also murdering you in the case of losing the random quantum bet.
like Schrödinger's cat you would only detect the world where you were not murdered and therefore made a profit.
Repeat until you are rich right? NO

For Goodness sake !

This is the time to say I strongly advise AGAINST any attempt to self harm or quantum probabilistic self harm, there are many good reasons to think this whole ordeal will not work, you can read all about it.

But for fun, lets assume it does work

Many of us might still feel uneasy with the thought of being murdered in most worlds, leaving our beloved family and friends behind in the vast majority of worlds having a very odd device attached to our corpse. 
easy... we can just have our Quantum Immortality Machine Murder them as well in case of a losing bet.
and now our confused and probably resentful beloved will "travel" with us to the worlds where the quantum bet is always winning.
for the love of everything that is holy DONT DO THIS, I want to assume I am talking to adults who know the difference between an interesting thought experiment and homicide.

And for Narcissists Introducing:
'Nuclear Quantum Immortality Hacking':

Great, we have made a machine that would transport us and everyone we love to a world we can engineer, sounds great if all of the assumptions we rely upon are correct (a big 'if'). but what if I am a narcissist, and dislike the idea of the rest of humanity escaping my grasp and judgment, I don't want to just disappear from most worlds, I want to impose my will on all humans.
Easy-peasy.. you just wire your Quantum Immortality Murder Machine to an arsenal of world ending nukes that would eradicate all life on earth. destroying humanity in every world where your bet lost, and now you can force every human on earth to live in a world of your choosing (just as god intended).

Did it already happen?

Another [fun] consideration is in the thought that we might already live in a world that has been subjected to "quantum selection".
Considering the very delicate and fragile mechanism of assured mass destruction in case of nuclear war, it is easy to imagine that in most worlds humanity (or most of it) went though a self eradication event, hence we can only detect those few rare worlds where Armageddon didn't happen. so even given the insane state of those weapons primed to start a nuclear winter in a matter of hours and sensitive to only a few bad decisions by stressful humans, even given this unstable state of affairs, we would only detect a world where disaster didn't happen.

I vote we don't rely on Quantum Immortality for self preservation.

Have a nice day