Why does DC waste three pages of space in my comics?

Back when both Marvel and DC Comics were inching their way to a cover price of $3.99 for a 22-page comic book, there was a pretty big outcry from fans.  This represented of a 33% price hike at a time of economic turmoil and it quite obviously wasn't very warmly received.

Because of the backlash, Marvel seemed to slow the rollout of these new prices to the point where there are still $2.99 books on the shelf (though they are being replaced with some regularity).  DC, on the other hand, brought nearly all of their comics back to the earlier $2.99 price and crowed pretty loudly about it - releasing ads proclaiming that they were "drawing the line at $2.99".  In general, this was seen as a win for the angry consumer, and for a while it was.  But fairly soon afterwards, DC revealed that in order to keep the price the same, they would cut down the page count of most of their books to 20 pages instead of 22.

Two fewer pages meant that DC was cutting out nearly 10% of the story (or, perhaps, forcing writers and artists to squeeze more material into 20 pages), but something like this might be the best compromise readers could have hoped for.  For a while, letters pages came back to take up those two lost pages.  In the last year, though, DC has been filling up their empty pages with spreads like the one at the top of this post - it's a cover gallery promoting the upcoming "zero month", something that DC did, oh, 20 years ago as well.

The two pages are very short on text - it's basically "hey guys, buy these!  See ya next month!!" and then a splattering of covers.  I get that DC wants to promote other books and events that are upcoming, but when I turn the page again, I see this:

It's another in-house ad with little-to-no useful information.  In this case, it's basically "hey guys, see you at Comic-Con lolz!" and then the convention logo, which takes up two thirds of the page.

Are these really necessary?  It seems to me like it's a monumental waste of time for them to even include these pages in the comic.  If DC is really hurting for money so badly that they have to trim stories by two entire pages, why not sell those pages for advertisements?  And by that I mean outside advertisements, not just pages that no one pays for and ones that don't add anything to the comic in general in terms of content or revenue.  It boggles my mind and is annoying as all heck.  DC, at least since it's been owned by Warner Bros., has always been a corporation interested in making money above all else, and I understand that that's the way it's got to be.  But it's seemed a lot more corporate lately.

I'm glad that Marvel, even though they're now owned by Disney, doesn't pull cheap stunts like this when there's no basis for --

OH DAMMIT!