A common reader would – in most cases – don’t care, but I don’t think it’s the right way to pose the question.
This was a common situation with many italian comics: there were certain advertising inserts which were added only for a small portion or the print run, or in certain regions of Italy, or more than an insert in the same issue according to the zone / circumstance etc.
Generally speaking, what is part of the book are the ads which are printed in its pages… added portions which are 100% advertising, and not officially "endorsed" by the publisher as part of the "in-built" advertising are not part of the comic in its essence, but an added element. Obviously this is relevant for a collector, especially on an historical perspective, but since they are additional I believe it is fair that they just demand a premium but they should not be considered "part of the book" in its organic.
Here the issues without these inserts are the rule and considered complete, but of course certain collectors are willing to pay crazy prices for these.
There are also other cases, where the element/insert was actually part of the book (like the ASM tattooz, for example), but we have cases in Italy where the gadget/insert is SO rare that a copy with the gadget is considered an exception and often is proposed by a dealer which manages to find a copy at 80-100 multiples of the normal price (i.e. a 10 Euro book is offered at 1000 Euro).