To be honest, Pandora has served that role for me over the years. I am always amazed to look back at my Pandora station history to see how it has evolved into different streams/genres, all stimulated from hearing new music through a Pandora channel, and then starting a new station after I liked it. This has created a web of new music I wouldn't have sought out otherwise.
Obviously, I do think that a human DJ may perform this role better in some cases/genres though.
Obviously, I do think that a human DJ may perform this role better in some cases/genres though.