Twitter—like other social media sites—has enormous potential as a sales tool. The micro-blogging service gives you a direct, unfiltered communication channel with both prospects and existing customers. It’s unlimited PR in 140 characters or less.

To maximize Twitter’s effectiveness, however, you need a following. And to develop a following, you need to post content (“tweets”) that your prospective customers will value.

With that in mind, here are 39 useful things you can post on Twitter:

    1. Tips
    2. Quotations
    3. Original thoughts, insights and opinions
    4. Lessons learned
    5. Humor
    6. Blog posts
    7. Photos
    8. Videos
    9. Breaking news
    10. Industry news
    11. Staff or organization news
    12. Complaints
    13. Compliments
    14. Event announcements
    15. Event reminders
    16. Event cancellations
    17. Contest announcements
    18. Contest updates
    19. Contest winners
    20. Links to valuable web sites
    21. Links to cool blogs
    22. Links to articles
    23. Mini book reviews
    24. Mini movie reviews
    25. Mini restaurant reviews
    26. Mini software or app reviews
    27. Word of the day
    28. Questions
    29. Requests
    30. Poll or survey results
    31. Other people you follow—especially on “Follow Friday” (#FF)
    32. Warnings
    33. Recommendations
    34. Challenges
    35. Invitations to meet up
    36. Freebies
    37. Promotions and sales
    38. Weather updates
    39. On-site reporting

Based on the people you want to attract, decide which of these items makes sense for you and start posting (“tweeting”) them regularly. In time, you’ll boost your following, your exposure, your engagement and your sales.

Want to see what I tweet? Follow me at @DonCooper.

What other useful things do you tweet? What have seen others tweet? Share them in the comments below!