1. Get famous.
Do everything in public and for the public.
The more people you reach, the more useful you are.
The opposite is hiding, which is of no use to anyone.
2. Get rich.
Money is neutral proof you’re adding value to people’s lives.
So, by getting rich, you’re being useful as a side-effect.
Once rich, spend the money in ways that are even more useful to others.
Then getting rich is double-useful.
3. Share strong opinions.
Strong opinions are very useful to others.
Those who were undecided or ambivalent can just adopt your stance.
But those who disagree can solidify their stance by arguing against yours.
Even if you invent an opinion for the sole sake of argument, boldly sharing a strong opinion is very useful to others.
4. Be expensive.
People given a placebo pill were twice as likely to have their pain disappear when told the pill was expensive.
People who paid more for tickets were more likely to attend the performance.
People who spend more for a product or service value it more, and get more use out of it.