I set up 3 wp blogs on same domain:
At the main blog (in root) i grab a news from audi & bmw with WP Matic, and automatic link to original post at other blog (bmw for example). Everything is on same database with different wp prefix, users are shared in all wp blogs. Everything work just fine but i do not know how to share cookies, so when user jump around those 3 blogs do not have to login again, and again, and again... how to set up that user can use a same cookie at all 3 diferent blogs??