(Core Set only perspective! (though I can't imagine it ever not being useful))
"This is not a drink." This card said to me when I first used it, "This is a moment. The moment where you put the future in your hands, when stop doing nothing, and take control. You've only been half alive until now, nothing in your mind but apathy, lethargy and fog. Now comes the fire. Now you come alive. As that cool, carbonated liquid (with a hint of benzene) touches your lips and flows - nay, courses - through you, it's as if the dormant engine within you has ignited into life. That almost guilty shudder isn't a heart attack*, it's you casting off the dust and apathy from your life. (*it might actually be a heart attack. Drink responsibly).
Now feeling rushes into your limbs, your fingertips buzz with creativity and your mind reaches into the infinite for the next move, your next move. You are imbued with the light of imagination. You can do anything. You can go anywhere. Your life is YOURS, you've just never realised it until now. This drink was but the fuel to get you started. So, newly awakened one, what wonders shall your mind envision? What 3 miracles shall you perform today?"
I then learned the importance of proper shuffling.
Energy-drink fueled visions aside this is a great card for any faction. You won't get the precision of something like a Special Order or similar 'tutor' card, but you will skim through a fifth of a standard sized deck if you play all three, likely putting what you need into your hand through sheer force of numbers.
You can also think of it as a magic potion, putting yourself back into safe levels after a bad hit of damage, with the added bonus that you might draw into some burst economy to keep your momentum going. Against corps like Jinteki, who buy time with money and damage against the runner, a spare diesel can allow you to barely stop for breath.