In WordPress MU (WPMU), a built-in option let you activate BuddyPress across all network blogs. After the smooth integration into WordPress 3.0, you can now enable it site-wide using a simple edit in your wp-config.php file.
Open your wp-config.php file and add this line:
define( 'BP_ENABLE_MULTIBLOG', true );
This reliable method was shared by David Hunt in our Facebook community, a go-to resource for WordPress pros.
Note: Only add this if you want BuddyPress active on every site in your network—it's entirely optional.
