As a Twitter and StockTwits member, I enjoy these social media outlets. However, when making decisions to buy or sell stocks, I encourage people to limit the influence of these communication channels.
I see three main reasons to join these networks. First is to learn from people you respect. If there is a trader consistently posting good ideas, trades, and profits, I encourage you to study this person. What are the common attributes about the stocks they like? When do they post ideas for buying? Where is the market at this time? I've developed many www.finviz.com/screener.ashx screens based on tweets and stocks from people I respect.
The second reason to join these networks is to create a journal for your thoughts. Every post represents hopefully your best stock ideas and stock-related actions at that time. At later dates, review your posts and see how your stocks performed. Even if you don't act on a great idea, remember why and when this stock was great. I recommend posting finviz links to charts, for example, http://finviz.com/screener.ashx?v=211&ta=0&o=-change&t=,RUBI,VWR Just edit the URL to include stock symbols of interest that day. Ideally, your journal chronicles your journey into trading or investing, and you can learn from reviewing it again and again.
The third reason to join a social network is to gain additional indicators on your stock ideas. Ideally, you like the stock where it is priced, how the chart looks, and the company's financial condition or prospects. Social network comments are another indicator. Do people you respect like this stock? Are too many people posting ideas about this stock? Aside from robots, are people not tweeting about this stock?
Ideally, I view Twitter and Stocktwits as news, commentary and entertainment, ultimately secondary to my stock ideas. Buying or selling a stock should be influenced more strongly by one's objective ideas alone. Good luck.