Well...
1. They clearly acquired this domain after it expired and it already had a decent amount of backlinks from high authority sites. (It was previously used as the domain for a prominent Donut Shop in Witchita Kansas)
2. They did some keyword research and put together a list of high-volume keywords that had very little competition.
3. They flooded the site with content for all those keywords.
4. Then they continued to build more backlinks, from the looks of it - through HARO (business insider, wikipedia, msn, nbc, do-follow links) or a pretty pricey intermediary backlink provider.
tlldr;

Acquired an aged domain with nice existing backlink profile

High volume/low difficulty keywords targeted

Flooded the site with content for these keywords

Substantial backlinks built from additional high-authority domains
...and the cherry on top:

Highly relevant exact match domain name (to the majority of initial keywords they probably targeted)
This person/agency knows what they're doing and has probably done this before.
It's all there.