Which is DRM free, so I'm not tied to a specific store that may vanish out from under me leaving me comicless.
And with regular deals, so I get to pick up TPBs for $4 sometimes.
And really, really easy to use. With comics in EPUB, PDF, CBZ and CBR formats - and a button that allows me to put them into Dropbox _from their site_.
So now it's trivially easy for me to get an email saying "Special offers on Robert Kirkman/Ed Brubaker/Jonathan Hickman/Brian K Vaughan comics", (Plus something called "Monstress", which looks intriguing) spend $60, and have a Dropbox folder full of comics on my PC fifteen minutes later.
It's slightly more clunky to then transfer them to my tablet. But that's because I haven't gotten around to making the syncing work better for that.
I can see that this is going to be an expensive habit. Albeit one that doesn't take up too much shelf space (you should have seen the look on Erin's face when I told her I'd bought 12 TPBs...).
Original post on Dreamwidth - there are comments there.