According to reports, Twitter (TWTR) has sent out a survey to garner interest in a premium version of TweetDeck for professionals. A proposed view of he updated screen is below:Supposedly, Twitter has asked the interest in professionals paying a subscription fee of $19.99 per month that includes several features including an ad-free experience. The proposal in the survey is curious considering sports journalist Darren Rovell recently repeated a survey showing that around 35% of users would pay for the service. The suggestion was that a substantial amount of users would pay for advanced features including a more feature rich version of TweetDeck. A $20 monthly fee seems steep. Based on the calculations in the my article, fees could approach $5 billion based on the Rovell survey. If 5% of the current user base of Twitter paid say a $200 annual fee (discounted from monthly), the company would generate $3.2 billion in fees. 5% of users is probably high, but this is the amount of users in the survey willing to pay $5 per month for the existing service, much less advanced features that can be written off as a business expense. Moving to fees for premium services is a no brainer. The question now is whether Twitter can execute. Disclosure: Long TWTR