It doesn't have the flash in the pan moment of sucesss like a unicorn startup but these guys will make billions some day due to all the peering agreements and interconnect (most the long haul is probably leased), especially as IPv6 takes majority prominence in the coming years. Excellent slow burner kind of business and smart customer acquisition through low pricing and easy turn-ups.
The thing that makes HE unique is that they only sell full ports. They don't do fractional billing or 95/5. You pay for 10gigs on that 10gig circuit, regardless of use. This leads to networks running HE ports near max load at peak time. From HE perspective, this is great because it's super easy to plan for and scale out. You're never surprised by a customer who goes from 3 gigs to 92 gigs on that 100gig circuit.