They say that two things you should not discuss in a business setting are religion and politics. The reason for that advice is that people who disagree about those topics find it much easier not to interact at all.

And if you get into a discussion about politics or religion with a customer, partner, or fellow employee, you could lose the customer or supplier -- and if that fellow employee outranks you, you could be out of a job.

This comes to mind in thinking about the January 13 ad from Procter & Gamble subsidiary Gillette with a #MeToo edge. It's a short film, less than two minutes long, and it has stepped right into the middle of a hot political controversy -- attracting comments from people who support the ad and those who despise it.

The ad -- which keys off of Gillette's slogan, "The best a man can get" -- starts with stubbled middle-aged men looking at themselves in the mirror. Next up are short clips of boys bullying others, leering at women, and touching them in meetings -- which conclude with a man defending the conduct with "boys will be boys."

Then the ad shifts. A screen full of video clips conveys the reckoning of the #MeToo movement -- and, most powerfully, zooms in on the faces of young men registering its emotional impact. From there, the ad features short clips of men showing other men and boys how women should be treated and how to avoid bullying and physical confrontation.

The ad concludes with a focus on the faces of boys and the screen concludes with a call to action: "It's only by challenging ourselves to do more that we can get closer to our best."

The passionate response

Some -- like celebrities Rosanna Arquette, comedian Pete Dominick, screenwriter and director Jeffrey Reddick, Arianna Huffington -- supported the ad. 

Others -- including Trump supporters like Piers Morgan and James Woods -- hated it. Morgan tweeted that he found the ad "pathetic," "virtue-signalling" and "a direct consequence of radical feminists" who are "driving a war against masculinity." He and Woods both said that they might stop buying Gillette products.

Gillette has boosted revenue recently. In the latest quarter, it reported a solid 4 percent sales increase due to "improved consumer value, product innovation, investments in direct-to-consumer programs, and increased pricing in certain markets," according to the Cincinnati Business Courier.

But all is not well over the longer term. As The Wall Street Journal reported, Gillette "has been losing market share to online upstarts like Dollar Shave Club and other smaller brands. To compete, Gillette has been cutting prices and coming up with new ways to attract customers, such as personalized 3-D-printed razor handles."

Is this controversial ad good for Gillette's business? What lessons can business leaders take away from the controversy the ad has generated? 

Here's the most important takeaway from this controversy.

Focus on the customers with the most lifetime value

You can't make every potential customer happy. And a controversial ad like Gillette's is sure to make some people eager to buy your product, many happy to comment on the ad but not change their purchasing habits, and a few angry enough to stop buying the product.

The key to understanding why Gillette decided to do this ad is that it segmented its customers on the basis of their lifetime value -- the amount of revenue it believes its customers will generate for the remainder of their life.

This concept works if it's possible to hook a consumer when they first start shaving and keep them buying until they stop. Naturally, younger consumers -- such as Millennials who care about a company's values and the boys highlighted throughout the ad -- have the biggest lifetime value.

And the crotchety old men who have been buying from Gillette for their whole lives are likely to be far closer to kicking the bucket. While a few of them may give lip service to boycotting Gillette, odds are they will keep using their unused blades and by the time those blades are used up, they'll be outraged about another ginned-up controversy.

If the controversy around this ad brings in more Millennials and first-time shavers, it could bring P&G more customers with a higher lifetime value than the likes of Morgan and Woods.

The lesson for your business is simple: Use controversy if it will bring in more customers with a higher lifetime value.