A hashtag is a way to add "context and metadata" to a post on twitter.
Brand tags indicate that the tweet is intended for an ongoing conversation around that brand, and it can be measured for brand approval. Since every post on Twitter is public, unless the user has protected their updates, we are able to pull in a variety of search terms into our brand channels, including the brand tag. For more on hashtags and brand tags check out the presentation below.
RT @JessicaNorthey @zaibatsu: ALERT: @montanamonica's daughter is missing! Last seen in the Seattle area http://bit.ly/d0a1EN Please PLZ RT
2010 Amsterdam Global Conference on Sustainability and Transparency http://ow.ly/1PYm3
How not to get “brandjacked” like BP Global PR http://ow.ly/1POz1 by @thebrandbuilder via @byrnegreen
Making and Measuring Online Buzz: Learn how brands can best use social media to create conversation #SB10 http://bit.ly/sb10_program
Subvert and Profit: Are you friends getting paid to Like you? http://bit.ly/bqdImQ #transparency