No one debates that there are legitimate returns from social media marketing. These returns often come in the form of a short burst of traffic and/or an increase in links. That can improve your search engine visibility, but small businesses, in particular, still have to ask: Is the return greater than the investment of time and money?

For what it's worth, I agree that nearly every business, big or small, unsexy or not, can come up with something that's unique and linkworthy—something that will play well on Digg, YouTube, or whichever social media site offers the best audience fit. I also think it's imperative that small businesses use social media marketing in order to decrease their reliance on traffic from one or two search engines; you have to diversify to survive.

1b. Comment on other blogs. You can't blog into a vacuum. Blogging is about creating and joining conversations, and that includes reading what others in your industry are saying and joining the discussion on other blogs. It's free, and again, the time investment is up to you. You'll be able to supply your name and URL when leaving a comment, and there's no debate that intelligent comments on other blogs helps build traffic to yours.

4. Take and share photos. I'm a longtime believer in using Flickr as a marketing tool. The time and cost investment is minimal. And thanks to Flickr's incredibly active photo groups, you can share photos of your products with people who are interested. A pet store owner could share photos with the 2,000+ members of the pet parade group, which is one of dozens of animal-related groups. A company that makes iPod accessories could post nice product photos in the Apple group, with its ~2400 members. And a construction company that makes custom homes could post photos in the appropriate city group, like San Francisco or Chicago. For more on this, I invite you to read How to Market on Flickr on my blog.