Tamar Weinberg is a freelance writer, blogger, and social media strategist. Her specialties are blogger outreach, content promotion, community management, and viral strategy. In July 2009, Tamar published “The New Community Rules: Marketing on the Social Web ,” which covers the gamut of social media marketing  topics in an easy-to-understand format. Tamar is also the community and marketing manager for Mashable, the top ranked blog on all things social media. She maintains her own blog on social media marketing strategy at Techipedia.com . Follow her on Twitter at http://twitter.com/tamar/ .
You're active on "many social communities," according to your website. Which one do you find to be the most valuable for business? What about for personal stuff?
It really depends on the content. In most cases, Twitter is valuable for both business and personal stuff. My @tamar Twitter account is mostly business-centric though -- people follow me because I'm into social media, not because I'm a mom. As a proud mommy, though, I occasionally provide some parenting and mommy-centric tweets.
For personal stuff, Facebook is the best. I recently came out with a post that explains how I use social networks , particularly Facebook, and to a lesser extent, LinkedIn. It can best expound upon my answer to this question.
What are some ways to measure return on investment from social media marketing?
The biggest challenge is that there's no direct way to measure social media ROI . But you can absolutely see if you've made waves. You can calculate reach (the length that the message travels), frequency and traffic (how often someone visits the page you're bringing attention to), influence (the depth of a conversation, especially as it refers to positive or negative sentiment), conversions and transactions (will they buy?), and sustainability (will they last beyond the campaign?). You have to keep in mind that awareness may not be direct, though. I might see a great link from you but not buy from you until I have a need 6 months in the future. However, there are things you can do now to measure the effectiveness of that viral story or even an online interaction.
How does social media change the link building game? What are some strategies for getting "social links"?
I'm not sure if it "changes" the link building game. It enhances it by putting a focus on content instead of pure link building. In fact, it compels you to write content that you believe site owners, bloggers, and influencers will link to and share with their networks. That is part of the strategy: if you write good content that is shareable -- that people want to talk about -- you'll see it spread. And you can be part of that too by submitting your articles to social news sites. Just make sure that the sites you submit to are receptive to your content.
What about social media and reputation management? How can companies and brands control real-time spam?
Social media is perfect to help tackle reputation management issues. You can build up active social profiles on various networks and engage to help remove those negative search results. Better yet, just be proactive -- respond to concerns to avoid that reputation management issue to begin with. But if you're already there, active social profiles and consistently churning out good content is a great way to push those results down.
What's the low-hanging fruit in social media optimization (SMO) for a business just beginning to establish a social presence?
It really depends on where your customers are. Most of them are on Twitter and it'd be pretty impossible to say that they're not on Facebook. On both, encourage your customers to follow you and become a fan of your page. On Twitter, start searching for people mentioning your competitors or product names and jump in to help when you can. Engage your communities. Give of yourself and the rest should follow.
Assuming your job wasn't on the line, what would you say to a manager who banned social apps like Twitter and Facebook in the workplace? How can savvy employees make a business case for social media marketing?
I can understand the case against social media in the workplace. It's a waste of time and most spend their time dabbling in personal pursuits and not professional ones. But if they are really so deeply involved in the space that it bothers them enough to log in during the workday, you should get the clue that they should be your company evangelists. They're your marketers who can already boost your business without you actually having to hire marketing expertise. Train them and give them the keys to promote the company.
Any tips for gaining followers and authority on Twitter? What factors determine whether or not you follow someone on Twitter? (You obviously don't follow everyone who follows you!)
Everyone can use Twitter his/her own way -- my personal preference is the desire not to get too many DMs, so I've opted to use lists for more engagement among people who I think are brilliant in some way. As for followers and authority, my entire following has come naturally. I don't mass-follow and I've never auto-followed everyone who follows me, but I do engage as much as possible either directly or via DM (or even email after I see a tweet).
It's really hard to say what the "magic formula" is for Twitter. I recommend Tweet Spinner which I reviewed  just a few weeks ago. You can use it for setting up keywords you might want to use to establish a relevant following. It also has a nifty feature called "mimic follow" that's quite awesome -- you can follow people who follow certain users, for example.
What tools and apps (paid or free) do you depend on daily for productivity and generally making your life better and easier?
This one really deserves a whole other post, and I've been trying to do that for a while. For the most part, I'm reliant on Google Chrome (for speed), Firefox (to use Gmail and the RememberTheMilk's plugin, which serves as my "calendar"), Google Reader, Gmail, HootSuite, and Seesmic Desktop. And I'm a Windows 7 girl -- it's a fantastic operating system.