Complex sentence: In early June 2012, Tumblr featured its first major brand advertising campaign in conjunction with Adidas, who launched an official soccer Tumblr blog and bought placements on the user dashboard.
Split into simpler sentences: In early June 2012, Tumblr featured its first major brand advertising campaign in conjunction with Adidas. Adidas launched an official soccer Tumblr blog and bought placements on the user dashboard.