tumblr
Tumblr's implementing a pay to remove ads thing after they realized Post+ was doomed.
... I can't say I don't feel too badly for them because, as much as I dislike skeevy "pay to remove ads! Except these very specific sponsored ads that will still show up and defeats the purpose of an ad-free Tumblr subscription" I still love Tumblr. I'm incredibly active on there and its my first avenue of choice for social media slash multimedia blogging platform.
Plus it seems like its actually a good idea in retrospect. It also removes those pesky gross ads from mobile Tumblr too, which is helpful since... there is no adblock for the mobile app. You can certainly run Ublock Origin in mobile Firefox, but it's not the same as actually using the app.
re: tumblr
[image id: A screenshot from Tumblr. At the top is yellow text that says "Tumblr Ad-Free Browsing". Underneath it is white text that says "It's Tumblr, only ad-free. Ad-Free Browsing gives you more of what you love and less of what you don't. What are you waiting for? Its a whole new world out there." Beneath the text are two white buttons, one is labeled "$4.99/month" and the other is labeled "$39.99/year 33% off!". There is text underneath the buttons, also in white, that says "Subscriptions renew automatically. Excludes certain promotional content." All of the text is overlaid on a gradient background that is purple at the top and pink at the bottom. /end id]
re: tumblr
So. yeah. I can't fault the current owners of Tumblr for doing this. It could actually pan out to be a much better idea than like... Post+ or whatever other subscription models they could come up with.
Unfortunately, or I suppose fortunately, a large majority of the Tumblr userbase is actively hostile to and oppositions any attempt of monetizing the site. Because the original creator of Tumblr, David Karp, never really invested in monetizing what he had made. It was only when Tumblr was sold off and he took a step away from what he created did ads and other things begin to leak into the platform.
And then the great big porn ban happened and Tumblr... Is still largely the same, has a lot of the same problems, and porn blogs are still there. Tumblr is still widely considered to be unsuccessful when it comes to monetizing the platform, and it isn't as easy of a solution as just "Well, why not do what Wikipedia is doing and have Tumblr accept donations instead?"
At least blocking actually works, that's one of the greatest improvements I can say Tumblr has implemented within the last year or two.