Earlier in our month-long special report on the sharing economy, I wrote about how it’s the verticals– not the horizontal platforms– that are taking off as this trend gains steam.

Some of the biggest investors in the wave already spoke with us about why they thought this was playing out so differently from past consumer Web trends. But I decided to ask our sharing economy CEOs and cofounders about the phenomenon as well.

It was an interesting conversation, given our four guests fell equally into both camps: Lyft and Nextdoor are verticals and Zaarly and TaskRabbit are horizontals.

“This is the one all smart investors ask,” says Bo Fishback of Zaarly. For his part, he recounted advice his board member Meg Whitman gave him early on. When she joined eBay, founder Pierre Omidyar had done everything in his power to keep eBay a platform. The first thing she did was focus one verticals after another. While a jarring change, both believed that the focus on horizontals first and then doubling down on specific verticals was what made the company so strong, Fishback says.

There are plenty of examples like eBay in the past. The question is whether the sharing economy– and the Internet a decade later– are just fundamentally different now.