Targeted advertising

One of the joys of the internet is the ability of retailers to hone in on one's interests and to recommend titles that will be personally attractive. I just found on my computer this screen-grab of an Amazon advert for my own book from when I was looking at YouTube a couple of years ago:

Norah Blaney and Gwen Farrar, incidentally, were a double-act of the 1920s, singing in variety theatres. Blaney, who retired from the stage in 1932, later remembered a promoter of the time explaining their appeal: 'Norah fills the stalls with all the young men, and Gwen has all the lesbians in London come to see her.'