These types of absolute or bonded triple-net leases are sale-leasebacks. They are signed by or guaranteed by the parent corporation. In contrast, many at-market leases to say a Subway or Rent-a-Center for 5 to 10 year leases are signed by a local or semi-regional franchisee. Not the national parent. That explains 50 to 150 BPs in the cap rate.
Secondly, unlike at-market buildings, investors see these bonded NNN investments as having no vacancy, no lease-up costs, no turn-over, no ongoing leasing brokerage costs, no capital repairs during the leasehold, no interruption in rent if the building is damaged (e.g., sewer backup or roof collapse), and no landlord operating expenses that leak through in the so-called at-market NNN lease. Rent is just pure NOI.
They are an ingenious way for a national/international credit mega-corporation to leverage the strength of their corporate balance sheet. (Investors assumes of course that their model is sustainable in the very long term and will not implode like Blockbuster. I am always amazed at the enthusiasm of investors to price things to the hilt.) The corporation oversees via a private developer the construction of a building that costs say $4.5 million, including land, and they sell it for $5.5 to $6 million. This cash in-flow can then fund future expansion. Because the leases are so favorable to a landlord and because of the perceived strength of the corporate balance sheet, a 5% cap on say a Walgreens takes on the characteristics of a long-term corporate bond, but is directly secured by real estate unlike a general obligation bond. Even better, it avails of the 1031 tax deferred exchange laws.
Nevertheless, absolute triple-net leases are still a leased fee valuation with a large negative leasehold. They are not an intangible asset or a going concern. It is just a highly valuable LF distorted from market norms. At the opposite end of the spectrum, a $1 per year lease for 99 years made to a cherished charity or religious organization has the affect of giving away the property. There is no intangible asset value, just a large positive leasehold equaling, more or less, the hypothetical equivalent fee simple estate.