One of the problems with multinational online retailers' algorithms is that they've got no sense of humour. I use - when unavoidable - the most famous books-and-everything store. It remembers what I've looked at. So when friends (i.e. Emma) 'humorously' recommend things they know I'll hate, such as this:
then my browsing history of expensive camera lenses I can't afford, books like Cartwright's How I Killed Margaret Thatcher (a vole can dream) and odd SF suddenly gets filled with recommendations like this:
which really isn't my thing. Reminds me of the time a kind person sent me a copy of Katie Price's Perfect Ponies. (Review: horseshit, dogfood, to the knackers' yard with it).