Curved screens provide an "immersive" experience, and allowing a wider field of view.
Similar to a movie theater having good and bad seats, there is an optimal position when it comes to watching TV at home. This optimal position is directly along the central axis of the TV with the central point of the screen at eye level. The screen curvature offers a more natural viewing angle and experience due to its lifelike perspective. The easiest way of experiencing the difference a curved screen makes, is by directly comparing the two types of screen side-by-side by starting with the flat-panel (running the same picture) and then switching to the curved panel. The added depth and perspective then becomes instantly apparent and the obvious choice.
Curved screens also allow greater range in satisfactory viewing angles and offer minimal trapezoidal distortion compared to flat-screens. A [16:9] 65" curved screen TV versus a 65" flat television viewed from 4.2 metres from the centre of the TV offers 0.19 degree (~1%) greater viewing angle (based on Samsungs 4200R curved TV). Curved TVs also offer minimised glare from ambient light.
At first Curved screens were seen as gimmicks, but have taken off commercially and had gained acceptance so fast that most manufacturers are now rushing to bring a curved offering to market.