Why might someone prefer the top-down method for market sizing over the bottom-up approach? From what I gather, the top-down method involves using a larger data set and applying a percentage to determine a specific market size, like estimating the number of smartphone users in a city based on the city's population and the national smartphone penetration rate. In contrast, the bottom-up method seems to be more detailed, as it would involve estimating the number of smartphone sales per store in that city and then multiplying by the number of stores. Could you provide another example where the top-down approach might be advantageous compared to the bottom-up method?
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