In popular business vernacular, a "unicorn" is a rare type of privately-funded company valued at over one billion dollars, a phrase coined by venture capitalist Aileen Lee. Now, however, it has become clear that they are not exactly rare these days. Back in the late 1990s, we could count the number of unicorns on two hands. Today, however, there are140 of them. What's more, today's unicorns are remaining private far longer than their earlier counterparts--most with an average time-to-IPO of over 7 years, which ismore than double what it was back in 2000.

It's easy to see why companies like this are opting not to IPO so soon. Going public is a process that takes months of effort and plenty of money. Furthermore, as a public entity, you're opened up to the scrutiny of shareholders and analysts, which forces CEOs to shift their long-term focus to the kind of short-term wins that please the public eye. Today's unicorns don't want that pressure--and luckily for them, neither do their venture capitalist investors. Private funding continues to pour in, massively eclipsing what the giants of the last tech boom received. Amazon, for example, went public in 1997, just two years after its first round of funding and valued atonly $440M. Meanwhile, Uber remains private six years after its inception, with a value ofover $50B. (That's triple what it was worth one year ago.)

But these kinds of economic disparities aren't just affecting how companies operate--they're affecting how they recruit. After all, without the right talent on board, these billion-dollar babies can't innovate and sustain growth. So how are today's tech giants changing the hiring landscape? And, more importantly, what does it mean for the rest of us?

1. They're dangling cash instead of stock options.

Back in the late 1990s--when IPOs happened weekly and everyone knew a millionaire on paper--companies in need of skilled employees attracted candidates with the promise of lucrative stock options. Lower salaries were acceptable when instant wealth was just around the corner.

But that doesn't work anymore. Most millennials won't stay at a company long enough to reap the rewards of an IPO that's five or six years down the road. They want money now. That's why, with seemingly infinite capital on hand, unicorn companies are shelling out cash, increasing bonuses, and driving up salaries at an unprecedented rate. Non-unicorn companies have a hard time competing on the same level.

2. They're getting more aggressive.

Today's tech giants don't care if you aren't looking for a job. If you're skilled, you're valuable--and thanks to sites like LinkedIn, you can expect to hear daily from recruiters on the prowl, especially if you're already working for a unicorn. In fact, poaching is so rampant that, in addition to raiding a number of engineers, bothUber and Airbnb have even stolen chefs away from Google in the last year.

This cocky behavior isn't entirely new to areas like Silicon Valley. But what is different,according to one New York Times article, is that today's unicorns can steal critical talent in droves, offering compensation packages few others can match. In a world already plagued by skill shortages, this aggressive hunt can quickly leave the kind of significant gaps that lead to a company's decline.

3. They're using location as a perk.

In the 1990s, Silicon Valley was the hotspot, and the unicorns of the day built sprawling campuses in suburban areas like Santa Clara and Sunnyvale. But that's changing. Today, most of the vital, young talent lives in the city--and new unicorns know it. While many companies already established elsewhere now offer cushy shuttles between San Francisco and points south, the newer unicorns are setting up shop right in the middle of the most sought-after areas of an already high-priced city. And it's not just San Francisco. Similar scenarios are unfolding in areas like Boston, Los Angeles, and New York City.

Certainly, for the talent that resides in these urban locations, the convenience of having your office around the corner is hard to beat. And younger employees want to work for hip organizations in cool metropolitan spots--not in yawning office parks. But at what cost? A new study by Zumper shows thateach billion invested into a local economy by venture capitalists brings with it a corresponding rent increase of $69/month for a one-bedroom and $99/month for a two-bedroom--and that's a pretty hefty hike in San Francisco, which saw over $22B invested last year. As such, Zumper says San Francisco residents can now attributeone third of what they pay in rent to VC funding. To put that in perspective, the average senior engineer at Airbnb who wants to live near the office needs to spendmore than 53% of her monthly income on rent alone. And as more unicorns build and renovate in city centers, we can only expect that trend to continue.

In short, today's unicorns aren't just wealthier and more ubiquitous than they used to be--they're reshaping the hiring landscape. They're driving up salaries, escalating rent, and intensifying competition to points that might not be sustainable over the long term. Only time will tell. In the meantime, however, business leaders would be wise to keep an eye on what's happening and adjust their recruiting and retention strategies appropriately.