QUOTE(Mika Kurogane @ Sep 22 2012, 09:39)

Depends on the use. Also, unlimited will eventually become limited to some extent because bytes don't grow on trees.
Yup, afaik Google+ gives you unlimited, up to a certain limit! That is, you can upload as many pictures as you want, but after X limit they will be resized below 2,048x2,048 pixels. Of course, Google+ is a social network so... you'd have to upload them to the social network and then use them.
Also by Google, Picasa offers 1 GiB unlimited resolution, after that, you may continue uploading but they will be downsized to 800x800 pixels at most.
But yeah, there's still "free" and "payment" accounts.
Bytes don't grow on trees but.
-> Even if they did, they'd tax you for gathering them.
-> The service is more than just bytes. Keep in mind, for example, that the service must be avaliable 24/7.
So free services always have a limit, and you need to consider that the only thing you're giving the company is a single number: +1 on their user count (Unless they have paid ads or such).