I'd say it's a particularly good service if you shoot the C41 B&W films like XP2.
I was think of using this service for exactly that.
I also think the prints from digital files service would be of interest to users of those alternative technology cameras who may like monochrome prints on 'proper' monochrome paper with no colour cast.
"People who say things won't work are a dime a dozen. People who figure out how to make things work are worth a fortune" - Dave Rat.