The Stacks, they are a pain. If you've never heard the term, it is in reference to the walled gardens controlled by Apple, Amazon, Google, Facebook, and Microsoft. Credit goes to sci-fi author/futurist Bruce Sterling who used it in his closing SXSW keynote this year. Here it is from the horse's mouth:
"[There's] a new phenomena that I like to call the Stacks [vertically integrated social media]. And we've got five of them -- Google, Facebook, Amazon, Apple and Microsoft. The future of the stacks is basically to take over the Internet and render it irrelevant. They're not hostile to the Internet -- they're just [looking after] their own situation. And they all think they'll be the one Stack... and render the others irrelevant.
While I whole heartedly agree with his characterization of the Stacks's intent, I am not sure they are all equally bad or competent at locking everyone else out. Witness the greatest offender: Apple. For me iTunes is so broken these days that its core functionality has been completely unbundled by better alternatives. I get my music from Spotify or Pandora. I listen to podcasts via iCatcher. In both cases the network has enabled a different kind of design center which allows third parties to beat the native apps on the Stack.
In some cases you truly are stuck on the Stack. I use iCloud (which is in most ways terrible) because it backs up my iDevices in a way nothing else can. I also use iCloud to sync my bookmarks and photos. I could use Chrome and rely on Google's Stack to sync my bookmarks but I don't because it is not "better enough" than what is native to the Stack (Safari). However I'd gladly use something to sync my photos if— like iPhoto— it could sync natively the photos taken from all of my devices.
In case it is not clear, I love the concept of the Stacks. I just think we ought to get a lot more granular about the places in the different Stacks that are still viable attack surfaces for the creativity of third parties. These may change quickly as the Stacks grow and extend into popular use cases but one thing that can't be denied is that the folks that exploit the openings (Dropbox, Evernote, Instapaper as examples) create tons of value along the way.