Apple bought RAM, CPU, NAND, LCD, etc. mostly from Samsung for iPod, iPhone, and iPad, but has been diversifying the sources since Samsung started making and selling their own Android-based devices. The assembly was mostly done at Foxconn and Pegatron.
Matsushita on the other hand is one of the oldest Japanese electronics companies, and designs and makes millions of times more things than Apple. The relationship is like this: Matsushita - Samsung - Foxconn - Apple - Newegg - Myce - Customers so comparing Apple with Matsushita is not proper. What Apple does is more like what G.Skill and OCZ do. Anyway, it was Matsushita and NEC that initially lead the CD writer and DVD writer global OEM markets, but only when the unit cost was US$10,000, or US$1,000, or US$100. There were more than 10 very famous and popular Japanese ODD makers, and even more not-so-famous makers, but none of them could compete when LG Electronics and Samsung Electronics were selling hundreds of millions of drives at US$10 each.
Apple made their computers in the US like 30 years ago. All those ODM and OEM manufacturers have done far more things behind the advertisements and news and reviews on the hardware websites. Even relatively minor makers like ZTE and Huawei have begun in this year some appearances on the global forecasts and market share lists.
Apple still is the sexiest - and thus the most expensive - brand name in today's world, but the combined global PC market share of Lenovo, Acer, and Asus, the three leading PC makers of the Greater China is now larger than the combined share of HP and Dell. When armed with polished looks and flowing tongue, the third-tier and fourth-tier manufacturers will begin to mean much more in both news headlines and earnings reports.