Website traffic can be increased by various on page and off page activities. Various link building techniques such as guest posting, article submission, social bookmarks and classified ads help to generate good traffic. Social media optimization also helps to generate good traffic.
If the key thing here is "immediately" then you'll want to do online Ads at places you know your potential customers are. SEO works, but it takes more time.
1. Go with Google ad words PPC campaign!
2. Facebook Paid Campaign.
3. Use hashtags and engage with Twitter and Instagram in peak hours
4. Send Email Campaigns to targeted data
5. Write blogs with targeted keywords and rank it fast using platforms like medium. WordPress, etc
6. There are tons of forums relevant to your topic, choose those forums and engage with the audience by answering them in time