Small businesses are questioning the value of Twitter in an on-going debate on the new Marketing Donut forum.There’s no doubt that millions of people are on Twitter, including plenty of businesses. But many small firms are still unsure about the value of Twitter.The current debate on the Marketing Donut forum reveals that while there are some ardent Twitter fans in the business world, many other entrepreneurs are still asking how Twitter can help them.Marketing Donut expert, Mark White, runs Better Business Blogging, offering e-marketing and blogging services to SMEs and corporates. Twitter, he says, can be a powerful way for businesses to forge relationships but it must be used with caution.“Twitter is an excellent social-media based route to highlight and ultimately promote yourself and what you do,” says White. However, you shouldn’t sell on Twitter, he cautions, it is about relationship building. So what are the advantages of being on Twitter for an SME? “As your followers grow, it’s an increasingly attractive way to drive additional traffic to a blog or website by highlighting new posts or information,” he says.