Male interests usually fall along utilitarian bounds. Generally, we like things because we derive use out of them. The gym membership will get us jacked. The extra shots of booze for our buddies makes our night more fun. The BMW makes us more attractive to women (or so we think). The big-screen TV allows us to enjoy entertainment more.
Unless you are creating a product in a select few industries, to make money these days you must find something that appeals to women. In addition to receiving increasing economic "freedom" (i.e. purchasing power traded for the small cost of fertility, fitness, mental health, time, and happiness), research has shown that women control most of the purchasing power for households.
To sell something in a society where all of our material needs (and most of our reasonable wants) are satisfied, you need to find something that contains a superfluous, fun, fanciful element that women can latch onto with only the most cursory practical justification. I believe the best way to describe this superficial yet powerful female desire is "pageantry." Products that fit this description include:
Color Runs -- 5k races where people pay to get sprayed with colored paint. Prints money on 5 continents.
Locks Of Love -- A wildly successful "non-profit" (scam) that encourages girls to ruin months of work on their appearance for a donation whose monetary value could be earned through working an extra hour or so per week for the same amount of time.
Instagram -- A company that puts filters on pictures. Sold for a billion dollars.
Zumba -- A way to make aerobic exercise fun and less efficient by combining it with dance moves (slogan: "Join the party!")
The one thing these ideas all have in common is pageantry. Sure, Instagram helps girls get more attention and Zumba in theory helps them get in shape, but these goals are better accomplished in more direct ways that aren't as fun.
If you've come up with an idea or a product in the modern western market, the question you should be asking yourself is not "How can I sell this?" If you want to get rich, the question you should be asking is, "How can I sell this to women?"
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