Warning: session_start(): open(/var/lib/php5/sess_4g1dn3ahc6p2vt2befud6ho390, O_RDWR) failed: No space left on device (28) in /var/www/clicktotweet.com/www/index.php on line 5 50% of retailers admit they don't market differently to various demographic segments http://elstcp.at/1rUWnIF via @getelastic