Hi,
I'm using Deezer since I'm 13 (i'm 22 now) and never wavered. For almost 10 years I use your service and I love it, haven't used any other, ever. I just love the services you provide. I'm especially fond of the queue feature. I love that I can manipulate my queue any way I want, changing the sequence of the songs at will, adding and removing songs. I use it a bit like a playlist in of itself. I'm building it up over days, weeks even months, adding new songs I find over the time. Of course this whole 'playlist' is lost once I make a mistake and just tap on another song instead of 'play next'. Happens when my screen is wet and touch sensory is impaired, when other people do it because they don't know how I'm listening to my music or I just don't pay enough attention. Since there are a lot of songs in there and I'm often looping songs, they won't all be in the 'recently listened' playlist and I will lose most of the songs. That's of course my own fault, no problem.
But when I get logged out of Deezer because of a mobile switch or an update, my queue is lost as well. I think you can understand how frustrating it is to lose a playlist that's been built up for weeks and months because of an update.
So my suggestion or request would be, to either just keep the queues even after logging out and in again or to have a kind of 'recover feature' to get the queue and all of the songs back that maybe haven't been saved, as to not let them be forgotten for years.
A suggestion from a faithful fan of your service.