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I hate to say it—and maybe John will have some suggestions and prove me wrong—but it's exceedingly difficult to suggest keywords from outside the business. There's a lot to consider when choosing keywords including your (or your client's) business goals, products, and market, among others. You'll probably have to do some keyword research yourself. John shared the chapter on keyword research from out Beginner's Guide to SEO and I shared "Keywords to Concepts." I'd also recommend checking out this webinar on using your Moz Pro subscription for keyword research. A bit has changed in the app, but the advice still hold true. Otherwise, I'd recommend Google's Keyword Planner—it requires an AdWords account, but you don't have to be actively advertising—and Übersuggest as good tools for getting started. Good luck!

Hi There Josh has a really good point. Is that your site also? I'd also highly suspect some poor back links pointing at your site http://screencast.com/t/RbsezbmDwlVk as well as things like these active footer links http://screencast.com/t/BM7o0V8Z You are ranking on page one for "suntech engineers" - what other keywords were you expecting to rank for, that you are not?