The Marketing Environment.

Marketers cannot control external environment but they must understand the changes of external environment and the impact on target market. Creating new products Sony's marketing managers should be aware of these external environment factors- social, demographic, economic, technological, political and legal, and competitive. To succeed they need to collect and evaluate environmental information. 

For example,Sony changed the way people think about technology  when it came up with Bravia 3D HD TVs. Creating this product the company had to answer these questions:
-are people willing to buy the product?
-who's going to buy product? what target market and is it big enough?
-is economic environment in a god condition? is the economy in recession?
- do my competitors have similar products?
The target market of  3D TV consumers most likely would consist of young people, rather then seniors.
Marketing also depends on lifestyle of people. for example, people who dont spend to much time at home wouldnt spend money on 3D tv that they will barely watch.
Economic factors also influence the external environment. Because Bravia 3D tvs are not cheap not everybody will be afford buying it. People with higher income will be the major consumers of that product.  Also the target market may be reduced during recession, when the prices will go up.
Another factor that can influence marketing is competitive environment. There are a lot of different popular similar firms that  will also produce 3Dtvs. So Sony has t work harder to maintain its profits and market share regardless of competitive market.