One of the most important aspects to growing your online business has got to be content. Concentrate on efforts that will consistently grow your brand and your business and don't obsess with seo too much, use it reasonably. Search engine optimization should always be planned.
SEO marketing can often times make website owners obsess over certain efforts causing more harm than good.
Dont obssess over Google Pagerank either. People tend to get so focused over increasing that little number in the tool bar that they lose focus around actually growing their business online. Google Pagerank sometimes makes people try to cut corners which eventually will come back to bite you. There is no reason why you should submit your company to thousands of directories. There are some good quality directories and that's all you really need. Chances are the search engines won’t even recognize all the others. Too many directory submissions is a waste of energy so don''t put alll your focus into this practice.
One more thing, don’t worry about what your competitors are doing.