First of all know your product and its target market. If you will not target right audience for any marketing activities will cost you a lot more.
There are many online and offline activities which can give you more traffic and leads. Initially go with paid marketing such as Google Adwrods & Affiliate marketing because once you enter in to the market, no one knows you so its best to work on branding and getting sales through adwords. Gradually go with other activities such as general SEO activities, mouth publicity, print media ads and all.
I hope this will help to bring customers. These are the general activities that you should do but it differs from type of business so share your business details to give more detailed plan.