As a new dad living away from my family, here's what I want:

1. cheap storage. I'm willing to pay $5 for 100GB.

2. don't muck around with my pictures. I have a nice camera.

3. don't copy all of the pictures on my account to all my devices, I'm trying to free up storage, not consume it.

4. let me setup a slideshow on my TV easily. I have (multiple) game consoles hooked up (that have web browsers). I have a Chromecast. Music + pictures = instant emotional win! Just let me pick an album "start slideshow" and put on some cheesy music automatically.

5. Let me easily share albums with family/friends, and let them access the pictures easily

Right now Picasa + Google Plus is the closest. The one thing is that there is no good way to get a slideshow going on my TV. This is actually a big deal to me. I have a Chromecast and all the major game consoles connected to my TV - and there's still no good solution. OneDrive on Xbox One gets pretty close for TV slideshows, but then I have to upload an album specifically to OneDrive - which actually isn't too bad. But it's still cumbersome to get a slideshow with music going and because Xbox One doesn't do background music I have 1/4 of the screen taken up:

* load up music app

* find something to fit the "mood" which is annoying to do on Xbox Music

* go to one drive

* navigate to album

* start slideshow

* snap xbox music

> I'm willing to pay $5 for 100GB.

Well there's the issue. S3 rates are $3 for 100GB, which leaves $2/mo to provide the value-added services you enumerate.

You'd need 5k monthly subscribers just to hire 1 engineer.

If someone were providing this service at scale they'd get better pricing that $3 for 100GB. But you're somewhat right that the margins here are pretty thin - which is probably why the people that are providing the infrastructure are also providing the service (Google, Amazon, Microsoft). The margins are going to be higher for them, so it's going to be very hard for a startup to compete.

They just released Chromecast Backdrop, https://www.google.com/chromecast/backdrop/

Yup, I've been using that - but it's not really a slideshow. Each picture is visible for 20+ seconds, and there's no music. I haven't tested if you play music that the backdrop is still visible though.

Google+ and Chromecast are like 85% of the way there. I just want to open up the Google+ app on my phone, go to an album and "cast slideshow" and have that be a great experience. Right now it's horrible.

Have you looked into Picturelife? Their pricing is competitive and it has easy album sharing.