It’s all marketing. You likely only know that Dominos had the system patented because it slaps a big patent number right on the tracker. The fact that you're discussing it is essentially free advertising and increases brand awareness. So, this post suggests that the investment in patent lawyers was likely worthwhile for the company.

Largely, consumers seem to derive the below listed perceptions when they recognize that a product is protected by a patent:

1. When a message about a product being protected by a patent is conveyed, the company as a whole is perceived to be innovative

2. The patented product is perceived to be superior

3. The patented product is perceived to be unique, as no one else can copy the patented product

from https://www.invntree.com/blogs/using-patents-marketing-tool-good-bad-and-ugly

(this is not a defense of any of these practices; simply indicating what is going on here)