????Twitter最新的IPO申請文件更改、豐富了部分廣告銷售收入入賬的說明。

????7月份，這家公司在私下提交給美國證交會（SEC）的第1版IPO申請文件S-1中表示，Twitter并無一貫的政策來確認某些交易收入。這一版最初并未向公眾公開。這家公司表示，它的收入確認方法還在發展完善中。另外，當時也不清楚廣告主就相關業務實際將向Twitter支付多少錢。

????Twitter表示，它在計算季報時對于這些交易會使用“最佳銷售價格估算值”。而且，它計算估算值的方法可能隨時間調整。

????但到10月初Twitter發布公開版的S-1時，收入確認政策這部分已經發生了改變。有關“Twitter仍在努力確定如何估算從這些交易獲得的收入”這些文字消失了。取而代之的內容是，更詳細的介紹Twitter提到的那些交易的類型以及為什么收入需要估算。這一次，Twitter表示對自己的估算能力有信心。“我們相信使用（最佳銷售價格估算值）能使得收入確定與交易所處的經濟環境保持一致，”Twitter在最終草案中寫道。

????會計專家表示，如果不是負責監管上市公司信息披露的美國證交會要求，Twitter原本也許不會改變這些措辭。目前無法聯絡到Twitter就此發表評論。一般而言，企業從遞交IPO申請后到完成IPO這段時間不能公開發表評論。依照美國《創業企業融資法案》（JOBS Act），Twitter得以秘密遞交了第1版S-1。它后來決定公開這些文件。

????一家公司到底應該如何、以及何時將銷售額確認為收入，這個問題越來越是SEC和會計界的隱憂。美國財務會計標準委員會(Financial Accounting Standards Board）正在與國際監管機構合作訂立有關收入確認的規定。

????會計專家羅伯特?威林斯說：“這是個熱點話題。”

????大多數公司傾向于在實際獲得收入前記入一些銷售額。問題出在公司將交易記為收入后，實際上最后可能拿不到錢，也有可能因為退貨而退款。過去幾年最引人矚目的會計問題中有很多都是與公司確認收入的方式相關。比方說，團購網站Groupon就在IPO流程中被SEC要求重新報告收入。最初，它將所有來自客戶的錢都記為收入，包括稍后需要付給商家的錢。Groupon被要求必須扣除這些需要支付給商家的款項。

????7月份，IBM披露稱，SEC正在調查其公布云計算業務收入的方式。電動汽車公司Tesla則強調稱，他只記入那些已售出并已交付給客戶的汽車所取得的收入。

????Twitter至今尚未實現盈利。但它今年上半年的銷售總額近2.5億美元。而且，這些數字看起來增長迅速。

????Twitter大部分收入來源于廣告。但它與廣告主達成的大部分交易都不是固定金額合同。用戶查看廣告主的tweet信息時，Twitter會獲得一些廣告收入。如果用戶點擊這些tweet、轉發給他人或其他情形，廣告主會支付更多的錢。因此，廣告主與Twitter簽約時，通常并不清楚到底要付多少錢。

????Twitter changed and expanded the description of how it tallies sales from some of its advertising deals in its IPO filings.

????The first version of its IPO filing, or S-1, which it confidentially filed to the SEC in July but did not initially release to the public, implied Twitter did not have a consistent policy to determine how much it stated on its financial statements it got from some deals. The company said its method was still evolving. In the deals involved, it wasn't yet clear how much Twitter would be paid from advertisers.

????In these cases, Twitter said it would use its "best estimate of sales price," when tallying up figures to compute its quarterly statements. And the way it calculates those estimates could change over time.

????But by the time Twitter released its public S-1 in early October that section of its so-called revenue recognition policy had changed. Gone was language saying that the company was still trying to determine how to estimate Twitter's take on these deals. In its place was a more detailed description of the types of deals Twitter was talking about and why revenue would need to be estimated. This time Twitter said it was confident in its estimation abilities. "We believe the use of [best estimate of sales price] results in revenue recognition in a manner consistent with the underlying economics of the transaction," wrote Twitter in the final draft.

????Accounting experts say Twitter wouldn't have changed the language unless it was told to do so by the Securities and Exchange Commission, which polices public corporate filings. Twitter could not be reached for comment. Companies tend not to make public comments after they have filed for an IPO, but before they have completed the deal. Under the JOBS Act, Twitter was able to file the first versions of its S-1 confidentially. It later decided to release them.

????How and when companies count sales as revenue has been a growing concern for the SEC, and the accounting profession. The U.S.'s Financial Accounting Standards Board along with international regulators are in the process of setting revenue recognition rules.

????"It's a hot topic," says Robert Willens, an accounting expert.

????Most companies tend to book some sales before they are are actually paid for them. The problem arises when companies book revenue for deals where they might not actually get paid, or revenue for items that are likely to get returned. Many of the most notable accounting problems of the past few years have been related to the way companies count revenue. Groupon, for instance, during its IPO process was forced by the SEC to restate its revenue. Initially, the company had called all the money it got from customers as revenue, including cash that was later paid out to merchants. Groupon (GRPN) was forced to exclude the retailer payouts.

????In July, IBM (IBM) disclosed that the SEC was investigating how it reports revenue from its cloud computing business. Tesla (TSLA), the electric car company, stressed that it only booked revenue on cars that had been both sold and delivered to customers.

????Twitter has yet to turn a profit. Its sales, though, totaled nearly a quarter of billion dollars in the first half of the year. And they appear to be growing rapidly.

????Twitter derives most of its revenue from advertising. Most of the deals it strikes with advertisers are not fixed upfront. Twitter gets paid something when users see advertisers' tweets. But advertisers pay more when users click on the tweet or retweet it to others, among other situations. As a result, exactly how much an advertiser will pay is often unclear when it signs up with Twitter.