If you are not sold on whether Twitter is right for you, consider the cost of ignoring.
• $1million in sales for Dell (corporation).
• 200 copies of Steampotville sold in 15 hours securing a publishing deal (individual).
• New leads generated from a recent campaign ran by Vignette (medium sized business).
This shows size does not matter as much as participation does. A simple formula to evaluate using twitter might look something like this (opportunity cost - human resource cost) = Return on participation.
As with any formula you have to assign a value to missed opportunities. The sum of these in both hard and soft cost will help you realize the possibilities. Like many people, it may be difficult to fully understand the opportunities that are being missed. Start by actively monitoring twitter streams on brand, product and competitive mentions to get an idea of who is talking and about what. What I was able to determine from monitoring on behalf of my company is people were either needing support, interested in more information or ranting. Do not fear those who are not saying nice this, see my post on "Addressing negative comments head on"
Human resource cost
Social media cannot be automated. Twitter is about building relationships by actively listening, learning and participating with the community. To do this effectively a person or team needs to be assigned. According to Jet Blue's CMO they started with a single full time person and a couple of who had part time responsibility but given their success they will expand the use of Twitter deeper in the support organization.
Return on participation
The returns or business outcomes vary based on defined business goals, see "Moving beyond social media metrics to business outcomes". To measure activity on Twitter several tools exist. Trackable url's like bit.ly and Hootsuite provide insight to the number of links clicked, Tweetreach measures reach of tweets and using web analytics you can determine how many referral's came via Twitter.
Twitter is relevant to almost all businesses. How much time you dedicate is based on what you think the value of the missed opportunities are. Before getting started define clear goals, listen before talking and be patient.
Twitter, It's not just about lunch anymore.
Follow dirk shaw on Twitter