As technologies and consumer preferences change rapidly, it is generally difficult for consumer electronics companies to build an economic moat. The replacement cycle for digital appliances is usually four to six years, but as most products are commoditized, it is difficult for manufacturers to build an ecosystem that prevents customers from switching to other brands. As a result, Sony’s profitability in electronics has been unstable in the past, while its music, movies, and financial-services businesses have generated solid results.