Originally Posted by JARblue

NAS is connected to your LAN, so however fast the connection to your router is. Wired or wireless can make a difference as well as the NAS itself. High bandwidth (HD) streaming is something that needs thought put into these connections. Most photo hosting and light traffic use won't need too much bandwidth.

If you're hosting from the NAS itself, your internet upload speed is going to be the limiting factor. But you don't have to do this - you can use the NAS for storage and still use online services for image hosting and backup. I don't upload every picture I take to the web. I save them all on my computer (or NAS) and then upload specific, relevant pics as needed. Usually either through the forum or temporary hosting site like Imgur or tinypic. I use Dropbox and my online storage for more permanent sharing solutions, but I typically keep those private.