RBC Capital Markets analyst Mark Mahaney (who’s considered the best Internet analyst) revised his estimates lower following TWTR’s earnings report. Mahaney lowered his TWTR price target from $14 to $12. His revised revenue/earnings estimate for FY’17 is now currently $2.338 billion, whereas his non-GAAP EPS estimate is $0.35. He’s bearish on revenue, and is in-line with consensus on non-GAAP EPS. Of course, he takes on the stance that revenue deceleration is driven by a crop of factors that could prove difficult to mitigate in the near term, mentioning that the company is figuratively trapped.Here were some of the key points from his research commentary:Trapped…Not Trumped: On the positive side, we see enhancements like Alerts and Newsfeed Curation driving increased engagement among existing users. And TWTR is demonstrating an ability to manage costs – ’17 outlook for expenses to be flat to down 5%, with SBC down 15%On the negative side, we see no material new User growth and we see ad monetization increasingly challenged by competitive pressures from other Social Media & Video platforms. Our Consumer & Advertiser surveys provided evidence of this. Q4 EPS results provided more. Trump Tweets appear to have had 0 impact. We now see Twitter as a Trapped Asset. We believe that only a radical overhaul of the UI and value proposition could potentially grow its user base, but such a step would carry enormous risk in alienating core users and its current unique value prop – real time news & commentary.I think Mark’s right, it’s hard to imagine TWTR ever re-inventing itself, or demonstrating meaningful revenue acceleration in a scenario where user metrics continue to stall, as the app hasn’t really caught the imagination of most internet users. It’s likely a niche app with potential for further deterioration like the My Space narrative, but perhaps not as extreme. Even so, revenue deceleration makes it a very attractive target for shorts, and yes, Mahaney continued to reiterate his underperform rating.