For years, we've discussed millennials as if, at best, they were some sort of novelty. Or, at worst, an annoyance, a temperamental demographic that lived among us as cultural aliens.

But millenials are much more than a niche audience brokers are forced to deal with or employers have to live with. In fact, according to the latest data from the number-crunchers at Pew Research, millenials will hit 75 million strong this year, surpassing the dwindling boomers as this country's largest age demographic.

In case you're wondering, this group—loosely defined (for now) as those born between 1981 and 1997—continues to grow because of the burgeoning young immigrant population, according to Pew. Boomers, obviously, are starting to, well, die out.