It depends on the web page and the services or products that you offer. If you just have a handful of keywords though, it might be best to find relevant keywords or key phrases for them that you could use as well. This way, you will get traffic not just from your main keywords, but also for these relevant keywords.
It is most important that you target a particular set (3 to 5) of unique and result oriented keywords every page. Page optimization should be done based on the targeted keyword for your business. However, if you wish to target many related keywords for your business you may use the inner pages for optimizing different keywords.
It really doesn't matter if you put keywords on every page. It's what we call on-page optimization, and most internet marketers and SEO gurus are doing this for their website or blog.
Relevance and uniqueness play a very important role here. You have to segregate the keywords on your site pages in order of importance and their search density. By adding different set of related keywords on every page of your site, you increase your chances of showing up in search engines for search phrases related to your niche.
But if I add 3-5 keywords on every page, than I have to optimize those pages also on that keywords. It will require lot of efforts. And one thing I want to ask is that If I don't optimize these keywords will SE automatically catch up these activities.
To rank well on competitive keywords and phrases related to them requires a lot of planning and effort. Also, on-page optimisation if done well on all of the inner pages will help reduce your off-page efforts.
I just think to rank well for different keywords, the density has to be at least 2 percent, and good quality backlinks.
t will require lot of efforts. And one thing I want to ask is that If I don't optimize these keywords will SE automatically catch up these activities.
It is good to have a variety of keywords and it's usually recommended to have about 3-6 per page. The most important thing is that the keywords are relevant to your content.