Underestimating Social Media
Linkedin , twitter and Facebook all differ in the value they offer, however not using these as a strategic offering to get low cost leads and branding is a definite mistake.
Not Having An SEO Strategy
How will anyone find you if you don't have clear on page targeting?
Failure To Combine Push And Pull Marketing
All marketing avenues should be explored for maximum efficiency and ROI.
Not Having A Clear Value Proposition
What makes your offering special or different?
What are your marketing goals? What tools are you using to accomplish them? Let me know in the comments below.