If I post that to any social network it becomes a clickable link. If you click that, it searches for all the posts on that social network that have that tag.
You will only see posts that are shared publicly or to people you are connected with. For Twitter, everything is public. Facebook is the most "protected" since most people are posting only to their friends. But it is still interesting to use the # on Facebook and it will become more important.
5. What does it mean when someone says something like #Justsayin #dontblameme
It means that they are just adding some phrases to their post and saving spaces. Sure you could click and search, but the results would be meaningless.
- Trade Shows -- At #PPAIExpo, I met new friends by following conversations where #PPAIExpo was in any tweet.
- Articles -- I often search for topics like #CIO or #softwaredevelopment to see any interesting articles that are being pushed.
- Discovering new places -- If you are going to Tampa for business or pleasure, you could search #Tampa and discover the places using #tampa.
- Prospecting -- #marketing #tradeshows are great keywords to search on your social networks and get involved in the conversations.