well i've only just begun so no doubt it will change a lot. but right now it's a combination of scraping/crawling for tracks and manual curation. i actually listen to all the tracks and nuke ones that don't measure up and change the order to mix it up a bit. the goal is to have a playlist every day of some quality tracks that you can consume in a sitting and hopefully walk away with two or three you really liked.
.io domains are currently pretty useless because Google webmaster tools won't let you target a global audience. So no one apart from those who live in the Indian Ocean states will find you via Google, which is a bit of a disadvantage.