Use Crowdfire to target Twitter followers. Plus, make some more twitter accounts (atleast 5) to push your main Twitter.
Include Facebook groups, followers and pages (boost posts) in your marketing as well as some like jacking fro your website. Expand and be consistent with the content.
Keeping your traffic consistent will keep your RPM higher than usual.
Every 24 hours your RPM stabilize. For instance, the more you share to targeted audience (best time - when most of them are online - early in the morning to the evening hours) and include some automation to repost on Twitter accounts and Facebook profiles and groups.
Use Google analytic to track your traffic - most importantly, the locations, browsing time on the website and bounce rates. However, targeting USA mainly means higher RPM as well.
Study more about Social media marketing and Search Engine Optimization (SEO).