First step - include link to your website in the profile.
This was the first thing I personally checked. :)
Try to talk to people who might be interested in your service on blogs and forums.
Try to participate in the events for your target audience.
Give your users referral bonuses.
One person at a time. You must know who your ideal user is, so now you need to go pound the streets and convince them to visit.
When I started my blog LeanStartups.com I went to every networking event I could and asked 1st time entrepreneurs and more experienced founders to visit it and give me some feedback. I "pimped" it to my friends on Facebook, tweeted, commented on blogs of others. I brought in one reader at a time. This way I have an organic growth audience, not just bunch of people who show up once and never again.
Peldi Guilizzoni (Founder of Balsamiq) wrote an excellent blog post on how he ramped for launch.
I thought the first post he referenced was one of the best - Press for Startups: 10 Tips by David Rusenko.
I've found that joining as many social networking sites & commenting on as many blogs as possible can also help. If you do so, you want to be real, though - don't just barge in promoting your wares. Add value to the communities you join, and you'll find that people are happy to see what you're up to.
Before you market your web site, make sure it is well done. There are many issues that I see with it, starting with I have no idea what the web site is for.
Read up on marketing a web site first, as suggested by the other people. And while you learn about it, get a good user interface designer to look over your site. There are many things you should change in your current design before you invite people to look at it.
SEO is a good start but it's not everything you need to do. Your best bet is to apply Inbound Marketing Techniques. The best resource I have found for that is this site.
Aside from that, Sasha makes an excellent point about talking to people who might find your service valuable. When I mean talk, that literally means pick up the phone. Doing that via email is good as a starter but you want to get people engaged with your offering and find some champions that will tell others. Think of it as finding strategic partners.
I suggest you do some usability testing first. I found it hard to understand what your website is about.
The key to low-cost & fast results on usability test is in the Don't make me think book. You can find it on sensible.com
My problem is the site that I cannot figure it out what it is about. The average user will spend about less then a minute looking at your site and if you fail to capture his/her attention then he goes away. I think this is the first thing you will need to fix. Just try to explain them what your site is all about,,,
Start by discreetly name-dropping your site in Questions such as this.
Read a book on the subject. I recommend "SEO: Your Visual Blueprint for Effective Internet Marketing"