By the mid-1960s unilateral deterrence gave way to 'mutual deterrence', a situation of strategic stalemate. The superpowers would refrain from attacking each other because of the certainty of mutual assured destruction, better known as MAD. This theory is still a major part of the defense policies of the United States and Russia. This led to the foundation of the nuclear triad, or use of three different types of delivery systems (bombers, missiles, and submarines), to assure that a second-strike capability existed able to cause massive destruction to the attacking nation.
What costs do they measure? The difference between cost per thousand (CPM) and cost per rating point (CPRP) is that CPM measures the dollar cost of reaching 1,000 members of the media vehicle's audience. CPRP is a relative measure of the efficiency of a media vehicle to a firm's target market.
What does ppm mean? This is an abbreviation for parts per million and it also can be expressed as milligrams per liter (mg/L). This measurement is the mass of a chemical or contaminate per unit volume of water. Seeing ppm or mg/L on a lab report means the same thing. One ppm is equivalent to the absolute fractional amount multiplied by one million. A better way to think of ppm is to visualize putting four drops of ink in a 55-gallon barrel of water and mixing it thoroughly.