When it comes to SEO (Search Engine Optimization), you need to be mindful not just of your Web site as a whole, but of individual pages within your Web site. After all, when you hear about getting your Web site to rank, do you know what that actually means? Well, it means a page of your Web site ranks -- not your *whole* Web site. For example, if you have a blog about desserts and you write an article about cupcakes; if someone sees your Web site in the search engine results when searching for "cupcakes," they're most likely going to see the article you've written about cupcakes -- not chocolate, candy, or whatever other delectable morsel of goodness you've created an article/page for. So, yes; your Web site is technically ranking, but more specifically, it's a particular page on your Web site that ranks for any given search term.
It is for that reason alone that you need to learn to think of your Web site in terms of "pages." Focus not on how you want your site to perform for every possible keyword you want to rank for, but rather, focus on individual pages that you want to rank for a very specific and limited number of "money" keyword terms (I'd say two, tops -- *maybe* three). Even the home page of your site should be optimized for very specific keyword terms -- not every single term you think is relevant to your entire site! After all, there's really no reason for someone to be taken to your home page unless there's something specific there that applies to what they're searching for. As a searcher, do you want to search for "cupcakes," be taken to someone's home page, then have to navigate your way through their site to the cupcakes page; or would you rather be taken straight to the cupcakes page and then navigate their site on your own accord should you be interested in anything beyond cupcakes? Surely the latter. With that said, you need to make sure your home page is set up like a portal and is easily navigable, but make your individual pages laser-targeted!
This is why "page authority" exists as a metric (there's also "page trust," but that's for a later post). You can have one page on your whole Web site that beats the pants off of all other pages on your Web site in terms of strength and popularity (determined *not* by the actual usefulness of your content, but by how many people link to you and the strength of the pages that link to your page). Because of that, if someone were to request a link from your site, it would be much more beneficial for them to have a link to their site on the most popular page of your entire site rather than anywhere else on your site. So, as an SEO, you're not just looking for any old page to build a link on; you want to find the strongest page(s) you can find on a Web site and try to get a link on it/them (but don't forget about "nofollow"/"dofollow" as even on the strongest page on the Web, a "nofollow" link is quite useless in terms of ranking).
So, as a Web site owner, make sure you have unique everything on each page and use your "money" keyword terms where applicable by way of your meta description, post title, the permalink (aka the URL, which is typically the same as the post title), page content, et al. Not only that, but if you utilize categories and/or tags and you place your "money" keyword terms as a category or tag for a particular page, then there will be internal links on other pages of your site pointing to that page of yours that talks about whatever your keywords are. Anything you can do to help guide search engine spiders to your content using relevant keyword terms is good. But simply optimizing your pages well just isn't enough in most cases. You will need to go out and garner some interest in your page! Get links pointing to your page -- preferably "dofollow" links that use a relevant page's "money" keyword term as anchor text (this is anchor text).
Think of your Web site like a yard sale: If you want people to show up to the right house (or Web page) in your neighborhood (or Web site), you put up signs that say "yard sale" (or a relevant keyword term) and you direct them to your address (or Web page). The more signs you have up in different places (or Web pages), the more people (or visitors/search engine bots) are likely to show up (view your page and/or crawl it).
And that's all why thinking on a page-by-page basis should be your approach to almost everything site-related; regardless of if you're a person/business running a Web site or an SEO looking for other sites to build links on. Now you're thinking in pages! :)
Questions or comments? Feel free to let me "hear" them below!