Let’s face it: You’re going to have to market products to people that you can’t sympathize with. It’s okay—you have a ridiculous amount of marketing data in front of you that says what every individual group wants, so you can make your product or brand appealing to them. One of things we like to do most is to group customers by age, and then market to them differently based on generational data.

Here’s why that isn’t always a good approach in our modern times. Let’s start by discussing how you decide what year a certain generation ended and another one began: Of course, there are certain major events in history such as wars, assassinations, terrorist attacks and the like that we use to group people and say, “They all experienced this so they all have the same values,” but that isn’t really how the world works anymore.

The Internet and mobile devices have changed the way information spreads, how media is used and what experiences people hold in common. Perhaps that is why if you look at a chart of the years that different generations change (Baby Boomers, Millennials, Generation Y) you’ll notice that different charts use different years. If we can’t even agree on who falls into which generation, how can we viably use that as marketing criteria?

Even if you could get the years that generations change down to an exact science, it still doesn’t change the fact that people are different within a generation as well. Has music changed over the years? Sure. But even within a generation, there are people who prefer different types of music—there were folks in the disco age that liked country music or were still into classical composers. While most people today prefer a beat to their music, some like hip-hop and others prefer more electronic styles like dubstep. You simply can’t define an entire generation’s tastes by the year they wear born; you may as well base your marketing strategy on the Chinese zodiac (note: please don’t).

Finally, don’t forget that even within a generation, there are people in different stages of life. Not every Baby Boomer is retired, and not every Gen Xer has a family. Behavior, rather than age, is a far better focus for marketers in our modern world.