I've created a filter in email that takes every email that comes in with the word unsubscribe in it and puts it in a separate folder.
On an almost daily basis I look at what's in that folder - and there's good stuff - Dan Pink, Ariana Huffington, Michael Bungay Stanier the list is long.
But what I also see is the offer for a radical innovation in men's skin care or an orthopedically designed mattress and a plethora of other stuff I don't even remember subscribing for
And if it is useless to me, I unsubscribe
As a result, my in box is less cluttered, I avoid paying for "first year free then only $3.99 a month there after" add-ons to the stuff I actually wanted, and just the act of unsubscribing leaves me strangely - and pleasantly - satisfied