Twitter's stock rose 76% this month surging 182% since the company's IPO in early November. The shares closed Thursday at $73.31, but on Friday some began questioning the company's business model, even calling it faulty after conducting a two-year experiment. Forbes Contributor Joshua Rogers tells us he has 1,201 Twitter followers. "Once I Tweet this article, three of you will actually read it (that's a 0.25 percent click-through rate)," he writes. "What does that say about Twitter? What does that say about me? What does that mean for Twitter stock?" I'm thinking what it says about Twitter, Rogers or the stock after finding his article through a search on google.com, not by following his tweets. For me, search engine marketing still makes the most sense for brands looking for new and existing customers. Social sites like Twitter can augment other media, but unless the brand builds a huge following on social sites, it will need another media to support the campaign. Macquarie Capital Analyst Ben Schachter Friday downgraded Twitter from Neutral to Underperform. In a research note, he says it's because the company has not changed since going public to justify the sharp rise in shares during the past few weeks. "We expect this to be among the shortest downgrade notes you’ve ever read, as nothing fundamentally has changed since our Neutral initiation on Dec. 11, except that shares have risen 40%," Schachter writes. "When we launched on TWTR 15 days ago, we laid out pros and cons and stated that TWTR was worth $46/share. Since that time, on the back of virtually no new news, the stock has risen in value 40% (vs. 2% for the S&P 500)." It doesn't mean Schachter isn't "bullish" on the company's future. He sees many opportunities, but it takes times and employees. He tells us Twitter has less than half the number of employees as Facebook and just 5% of Google's, even excluding Motorola. For anyone interested, The Verge has a lengthy article on changes and growth at Twitter.