That does seem to be the nature of the vast majority of so-called "special offers." Some of it seems to be outright scamware. You add some app that is authentically free, but in the process of downloading it... unless you unclick a whole number of agreements... you're being charged in the background for some kind of weird security software and "partner provider bundles" you didn't want.
RE: It's Only a Couple of Dollars! (and Other Fallacies...)