Complex sentence: Morgan Stanley estimates that Amazon sold $3.57 billion worth of Kindle e-readers and tablets in 2012, $4.5 billion in Kindle device sales in 2013 and $5 billion in Kindle device sales in 2014.
Split into simpler sentences: Morgan Stanley estimates that Amazon sold $3.57 billion worth of Kindle e-readers and tablets and will sell $4.5 billion worth of Kindle devices in 2013. It estimates $5 billion in Kindle device sales in 2014.