Memo to Twitter: with search, do not grow a brain. Partner with the best at Google and Microsoft (see Facebook-Bing), and you’ll get great AdSense, AdWords, display ads, and mobile ads without having to run all the infrastructure—and manage all the people!—to do it. They should be willing to give you 70% of the revenues now that you’re doing a billion searches a day.
Let’s say you can’t yet get the dime per search average that Google has spent a decade optimizing. Even if you only average 2 cents per search, that’s $20 million in revenue per day. Your cut? $14 million a day. That is real money: roughly $400 million a month, or $5 billion a year. And it grows as your number of searches and average revenue per search grow.