I lost about 3 years of data because of a misunderstanding with the cloud system.
I was preparing to migrate my data from my iPad to my cellphone, and so I saved it to the cloud. I cleared the data (I was going to give it away anyway)
Well, I didn’t get to download the data back to my cellphone as it was charging at the time (just plugged in in fact) and then played on the iPad for a while. The newly cleared save data apparently replaced my cloud save data as I pressed the Social Boat button.
When I got to my phone, I was surprised to see the save data. I actually didn’t realize that the cloud auto-saves when you open the social tab.
The latest save data related to the newly-gone data was saved 3 years ago. I lost a huge chunk of the game’s content. If you want to know how much I lost, let’s just say that the bridge to the island wasn’t built yet.
I was annoyed, but pretty much accepted that there’s no way I would get the old, wiped-out save data again. I lost about 3 years of progress, 8 levels, and a large amount of money just because of an autosave.
(P.S. The 7 day data limit doesn’t exist apparently. The 3 year old data loaded with no problems.)