Try paid search, social media and display advertising are great ways of attracting visitors
Write a blog and regularly post articles relating to your chosen industry i.e. news, offers, reviews, tips, faqs etc
Share content and engage with other people on social media, facebook, twitter, Linkedin, youtube and others
Guest post on other large websites in your industry, or vice versa, invite others to guest post on your site
Partner with a leader in your industry, for example, you could join up with a medium sized retailer and offer something in return for signups (you'll both benefit from greater exposure and leads)
Interview industry leaders
Create an email list and send out regular updates i.e. once a week
Create and promote landing pages offering guides related to your niche, this will help you build up your mailing list
Pay attention to SEO and target long-tail keywords