A light lager with a strong hit of rice and almost no hops taste whatsoever, Efes is a mediocre beer at best. It is often served ice cold to cover the poor flavor of added glucose, and metallic tinge of (presumably) ancient brewing vats. At a price of 4 lira for a 50cl can or bottle in the store, the beer is grossly over priced but no other options present themselves in Turkey because of high import tariffs and a nationalistic love of all things Turkish.
Additionally, a prevalent Muslim culture for the past thousand years has left few remnants of an alcohol appreciative society, so chalk it up to beer-ignorance if you please, but the Turks have had nearly 100 years of secular Independence to figure it out and have failed.
Other beer choices in Turkey include: Becks (brewed by Efes), Fosters, Heineken, Peroni, Miller (brewed by Efes), Carlsberg, Tuborg, Marmara Gold, and Skoll. Other specialty imports may be available in select stores for limited times but than disappear altogether for example, Berlin Lager, Germania, and Guinness.