I find that hiring people in a startup to delegate fundamental activities (sales, marketing, development) rarely works.
The reason is startups usually haven't figured out properly all what it takes to grow the business (like the right market, right message, unique value proposition, right feature set) and there's a lot of trial and errors. On the other side, when you bring in external people, you have to be clear on their goal, responsibilities, tasks, deliverables, otherwise they won't simply perform as you would expect.
I believe with some organization any startup can market itself successfully. I have developed a sort of "framework" of activities needed that you can try to adapt to your situation. The marketing part is
- PR and Journalist relation
- Handle customer feedbacks
- Social media activities
- Email marketing and newsletter
The key is try to be balanced and cover (at least initially) all the areas in the framework. For example, schedule 1/2 activity per week (or every 2 week, or per month) in each area.
The final touch is to measure/test the results of each activity (how many users did a blog post attracted? how many people read the news letter? how many inbound links from social media activities? and so forth) to be able to understand what's the most effective marketing channel for you.
At that point, when you know what works better for you, what gives you the best conversion, you can hire somebody to work on that specific area.