Amazon sells their e-readers and Fire tablets with and without special offers. Special offers, in the case of Fire tablets, are not intrusive. Tablets are multi-functional devices and the special offers that appear on the lock-screen do not interfere with the use of the device unlocked.
Kindle e-readers, in contrast, are single-purpose devices and turning on the device means returning to an e-book. Anything that gets in the way of this single-purpose does intrude on the general user experience. Special offers appearing need to be bypassed by swiping across the screen to bypass the advertisement to then return to an e-book.
The worse aspect of special offers on a Kindle e-reader is the advertisement banner at the bottom of the screen when navigating the Kindle. With the restricted screen estate of a 6 - 7 inches Kindle e-reader this is a nuisance. Special offers displayed on e-readers, in my view, are an imposition and should be removed altogether. A possible alternative might be to place a designated permanent icon to access special offers in the top toolbar.