Hello spanner62,
You haven't really explained what you are currently doing to get those visits, so I'm not sure what you already have/haven't done, but here are a few things that I would do in your situation:
1.) Check your analytics platform to see which of those 50 posts are generating more traffic; in my experience you will probably have 3 posts (plus home page) doing 80% of your organic traffic. Focus your future content on that info, and try top optimize those pages that are probably ranking already to increase CTR on search engines; main way to do this is boost keyword density in these money posts within reasonable limits (no more than 5-8%) and make sure to have appealing meta-descriptions that will not increase ranking but yes bring in more clicks.
2.) Social Signals; go build them. Twitter, Facebook Fanpage and Google Plus are my initial suggestions. Better focus on 2 or 3 that you can update on a regular basis; be clever, feed your post RSS to Twitter and/or Facbook to get a constant stream of content on your social sites. That way, you get "more bang for your buck" and your content will get more exposure. Work on building a following on these social sites, do not focus on numbers but on quality of followers and interact with them.
3.) Finally, link building. Start slowly with natural link pattern; I would go for small gigs, drip feeding variety of links (social bookmarks + niche relevant blog comments where possible). At the same time, work on manual links from good established sites in your niche. I know that link exchanges have been frowned upon lately, but still works form me as long as I do not have 200 links in my blog roll. Better to have 5 or six niche relevant links than 500 shit blogrolls.
Best of luck mate, hope this was of use.
