On page is all about tags, titles and keywords. Where as off page is all about providing best content and getting backlinks. So if you have effective words but not the content then visitor will left your site instant after visiting. So both appropriate and familiar word for driving visitor and useful and unique content to keep them connect with our site.
In Off Page optimization you should emphasized on Article Writing,Article submission , Manual Search Engine submission,Manual Submission to niche directories,Building links from niche Blogs,Discussion Forum postings,Managing Link Exchanges,Social Bookmarking Submission,Social Blogging,Video Submission and optimization.while On Page Optimization is about Meta Tag Optimization,Content Writing,Content Optimization,Optimization for Flash and Frames,Image Optimization,Navigation Structure,HTML code optimization.