英语翻译the agency's media planners will have to decide what per

英语翻译
the agency's media planners will have to decide what percentage of the target market they want to reach(how many people will be exposed to the ads)and the number of times they are likely to see them.Advertising people talk about frequency or"OTS"(opportunities to see)and the threshold effect--the point at which advertising becomes effective.How much to spend on advertising is always problematic.Some companies use the comparative-parity method--they simply match their competitors'spending,thereby avoiding advertising wars.Others set their ad budget at a certain percentage of current sales revenue.But both these methods disregard the fact that increased ad spending or counter-cyclical advertising can increase current sales.On the other hand,excessive advertising is counter-productive because after too many exposures people tend to stop noticing ads,or begin to find them irritating.And once the most promising prospective customers have been reached,there are diminishing returns,i.e.an ever-smaller increase in relation to increased advertising spending