I see this old thread doesn't even go as far back as I do with Piriform and CCleaner. I've purchased many "copies", both download and retail box. I still have an opened box I've installed from, and one unopened one from circa pre-2012 I believe. And I've known about (and used) CCleaner well before that (back when it fit on a floppy disk).
Of course, like most people, I did not save the published EULA from way back then. On the box(s), on the receipt I have from Jan 2013, nowhere is there any mention of a "subscription" - to any portion of the product. Updates, support, nothing, zip, nada.