That stuff looks ridiculous, considering in a wet area you're supposed to aim for 100% coverage and 75% in dry areas, that stuff looks like you'd get 20% coverage at best!!
I'm sure I saw something in a magazine once about a guy that was trying to start selling tiles with the adhesive already on the back, just had a fi;m to remove first. Same sort of lines but the coverage looked better, as you say though the walls would need to be flat.
Even on freshly plastered walls I still had the odd bow to contend with!!