I guess games are doing this or at least something similar with the DLC packs. You buy the game once, keep paying for the new variants(?) and specials. And you get bug fixes for these for free.
Everyone(well almost) wants a SPA or at the very least non reloading pages. No one wants to reload the page with every action they perform or if only a part of the area on screen needed to be updated and the page was reloaded anyways.