[zelphirkalt]

Reality check: So you have no forms any user needs to input anything into, because if you had any, then you would need a spam protection, lest your customer gets tons of spam. Cheapest one is probably Askimet, but that costs money for a business. So either you are talking about little blogs, or not businesses. In any case, probably real small sites of purely informational character without user input, otherwise it would cost something. Or you are letting your customers get spammed.

No real maintenance? So either you let your PHP version and plugins become outdated, or you sooner or later have to fix things breaking. Maybe you simply did not notice any breakage, because you don't do maintenance for customers?

A brochure website? Does that mean people enter their e-mail to be sent a brochure? (Then paragraph 1 applies again) Or brochure meaning, that you merely display information on pages and that's it?

I think for small info sites what you describe can be true, but for anything slightly larger not, especially not for small businesses.