If you are doing your keyword research there are probably words or phrases on your dream list that you are never going to stand a hope in hell of ranking for because Google's top ten results are dominated by big players. So should you just bin those and move on? Not always.
If it is highly unlikely that you can rank for a certain search term then the next best option is to be on one of the pages that is ranking.
The most obvious example of this might be Google My Places if you are a bricks and mortar business. Lets say you run a medium sized pizzeria in Dallas - well you are going to find it seriously hard to rank for 'Pizza Dallas' given the competition which might include mega sites like Tripadvisor, YouTube and mega food ordering portals.
So instead of doing SEO battles with these goliaths you "don't beat them, join them" and get yourself listed on those websites. You can then focusing on how to improve those listings so you're at or near the top - encourage customers to review you, add plenty of images, make your listings truly comprehensive - perhaps even pay to be at the top.
Being on a website which is in Google's top ten for a search term you want to rank for is known as Barnacle SEO. You're hanging on to someone else's rankings.
You won't get as much traffic as if you actually ranked in the top ten but if the chances of that happening are low then 10% of something is better than 100% of nothing.
Barnacle SEO is often overlooked by Webmasters because they are just focusing on their search engine rankings when really the aim of any website is getting the right visitors.
I get a constant stream of visitors to a website where I sell an ebook thanks to Barnacle SEO and it wasn't even my doing. An article in a national newspaper ranks well for a very competitive search term and in the comments of that article someone has included a link to the website of my ebook.
The visitors who come via this link are three times more likely to buy my book than those who come via Google organic search so I probably sell just as many books as I would if I was actually ranking for that keyword.
The core message here is that Barnacle SEO can not only get you 'sort of' into Google's top 10 but it can actually instill trust in potential customers and clients before they even click through - something they don't feel so much when they arrive at your site via organic search.
Don't underestimate Barnacle SEO, it can be a very powerful way to get the best quality traffic into your site.