Answer to Question 1
Answer: The point of FYI messages is not the content they communicate, but the consideration that they demonstrate in taking the trouble to pass it along. While telling a colleague about a film you think she'd enjoy doesn't lead to a direct business benefit, it can strengthen and solidify your relationship. This in turn will likely improve your ability to work together, and her desire to help and accommodate you in the future. They keep communication channels open, which is an important part of networking. And while they serve no direct business purpose, they make both parties feel good. You get personal satisfaction from writing the messages, and the audience will be pleased to hear from you. These messages do no harm and they may do a world of good.
Answer to Question 2
Answer: In a business environment an employee will have to modify her approach to IM if they want to project a professional image. One should begin by learning what the company's IM standards are, and then comply with them. If the company doesn't have formal standards the employee could follow these general guidelines. 1) Focus on business: even if coworker's IM status says he is not busy, do not interrupt with personal messages. Limit your workplace IMs to workplace topics. 2) Keep messages simple: IM users expect text will be brief and to the point. 3) Use a professional-sounding IM username. It should be easily identified and attached to a business email address. A combination of first and last name is a good idea. 4) Be professional and confidential. Assume that others will read your IMs, so use language that you would feel comfortable having anyone read. Never convey company-sensitive information. 5) Save important messages. If your messages are not automatically archived, keep your own records so that you can refer to messages in the future.