That depends on how you're generating revenue now, honestly.

Is this a product? Monetized content (ad revenue)? Subscription?

Of the many ways to increase revenue, the two that are probably most actionable are:

1. Increase your number of customers.
2. Increase the lifetime value of each customer.

Without knowing anything about your model, it's very difficult to offer useful suggestions for going about this.

I've worked with hundreds of clients on growing online revenues, so I'd be happy to offer insight for your site — let me know if you'd like to discuss further.

Good luck!