Costco's gas business works because it reinforces the membership model. The cheap gas is not separate from the warehouse business. It is part of why people keep showing up.
That is the point I keep coming back to. A strong core business gives you room to build adjacent economics that would not work nearly as well on their own. Costco does not need gas to be the whole story. It just needs gas to make the whole membership package feel more valuable.
What makes this interesting is the discipline. Costco is not trying to do everything. It is using one strong business to support another one that pulls members back into the system. That is a much better move than chasing random adjacencies because they look good in a slide deck.
The reason this works is that it is tied to behavior the company already understands. Costco knows people will drive for value, build routines around the warehouse, and renew when the membership keeps paying for itself. Gas supports that loop instead of distracting from it.
Free HubSpot workshopBring one HubSpot problem to a free 30-minute callA screen-share walkthrough of your portal with me, not a salesperson, and a short roadmap at the end. No contract or credit card.Book the free workshopThat is the difference between a smart adjacency and a random expansion. A smart adjacency makes the original business stronger. It gives customers another reason to stay in the system. A random expansion just adds complexity and hopes the brand is strong enough to carry it.
The lesson for operators is simple. If the core business is strong enough, it can subsidize a move into something adjacent and make the whole model harder to copy.
