June 13,2009 23:39
對Twitter 不利的數字
這是今年四月的市調，聽了在美國工作的大學同學才知道有高達60%的人用了twitter之後不再用了！
Currently, more than 60 percent of U.S. Twitter users fail to return the following month, or in other words, Twitter’s audience retention rate, or the percentage of a given month’s users who come back the following month, is currently about 40 percent. For most of the past 12 months, pre-Oprah, Twitter has languished below 30 percent retention.
因為Oprah有帶動twitter使用，在她宣傳之前的12個月，只有30％的保留率，她宣傳之後有40％的保留率。
To understand why this poses a problem for Twitter, check out the chart below. By plotting the minimum retention rates for different Internet audience sizes, it is clear that a retention rate of 40 percent will limit a site’s growth to about a 10 percent reach figure. To be clear, a high retention rate doesn’t guarantee a massive audience, but it is a prerequisite. There simply aren’t enough new users to make up for defecting ones after a certain point.
這個對於Twitter來說，為什麼是一個問題呢？低的保留率會限制網站的成長，reach只到10。雖然高的保留率不保證有很多群眾，但是這是一個不可或缺的前提條件。
(上圖這個表是跑整體social media的資料，所做的迴歸分析。然後拿twitter的retention rate是比對推估internet reach。如果你跟我一樣，問了一個問題就是：如果有一個新的social media網站只有10人，但是retention rate有90%，比對此表豈不會會出現很奇怪的結論？感謝Sean解釋，喚起我對統計的記憶。所謂的regression model是就現有的data算出一個關係公式，然後用r square去評估那個variable有沒有存在意義。所以我剛剛的例子屬於極端案例，算是outlier。)
Compare it to the two heavily-touted behemoths of social networking when they were just starting out. Doing so below, we found that even when Facebook and MySpace were emerging networks like Twitter is now, their retention rates were twice as high. When they went through their explosive growth phases, that retention only went up, and both sit at nearly 70 percent today.
此數字跟Facebook和MySpace當初剛起步時作比較，這兩個前輩網站的保有率都比Twitter高兩倍。當這兩家經過高速成長時其實，保有率數字只有增加，現在這兩個站大約有70%的保有率。
