Have you ever finished a large link-building project and have been disappointed by the results? Did you ever feel the links you got weren’t working?

Well, you’re not alone. The primary reason I’ve found people run into a link problem like this, is that they fail to understand that it’s not only that links matter, but that not all links matter equally. Sure, everyone in the search engine community understands that links are important. Not everyone understands though just how they are evaluated by search engines and how disproportionately different seemingly similar link profiles can be (hah! say that tongue-twister!)  

So let’s talk a bit about the kind of links you should actually be trying to get not only to collect links, but to rank.    

Followed links  

This is rule number 1: don't try to get no-follow links. Some SEOs object to this saying Google doesn’t really treat no-follow as it says it does, and that no-follow links are probably worth something. Probably they’re right in the first part. Google does seem to include no-follow links in parts of their algorithms, more on that in a minute.  

Still, this doesn’t mean that you should be spending your time building no-follow links. Quite the opposite, keep away from it. The exception is the no-follow link that actually brings in real traffic. Apart from that, building inbound no-follow links makes no sense. Test from last year and this all seem to show that Google simply doesn’t count them in their Page Rank flow model or anchor text recognition algorithms.  

The only use no-follow links can still possibly have is diversifying a site’s link profile and that’s the area you should be looking at, if you're wondering what no-follow links still could be good for. After all, there is no reason why Google should treat no-follow links which have been intact for years on prominent Wikipedia pages exactly the same as no-follow blog comment links. But apart from such high-trust pages, like certain pages on Wikipedia, don't waste your time on no-follows. 

[On a side note, it seems SEOmoz’s Domain Authority metric may not be properly (dis)counting no-follow links in its link evaluations at the moment – example. Be careful].    

Links that get indexed  

This is actually an answer to all the “Should I submit my website to link directories?” questions.  

Yes, but only if the directories are worth bothering with. And how do you know that? Well, many low and medium quality directories have an astronomical number of pages in their sitemaps (thousands of listings) but only enough link-juice to get a fraction of them indexed.  

Of course links from pages that aren’t indexed are worthless. This is the Occam’s Razor you should use when evaluating any low quality links. What’s the chance the page you put your link on will get indexed by Google in the next 2 months?  

98%? Ok, go for it. Anything less? Forget it.    

Links on power domains  

Getting links from power domains (even when your link is on an unimportant page) will probably be a healthy improvement to your link profile. How come?  

There are strong signals that search engines try to calculate an inbound spam-link mass for every domain, which then impacts its ranking potential. Obtaining too many fishy links can diminish your overall search engine optimization efforts because of increasing the spam score Google assigns to your domain.    

Power links  

Get those killer links. You can't rank powered only by mediocre links. Do you have to give something gold and shiny for the good ones? Well, if you have, you have to (note: SEOmoz has a slightly different stance on paid links in general than I have and I respect that, as it’s probably the best course to take in their case).  

Nonetheless, very little power links are actually free to get, so usually you might as well get over the I-better-not-pay-real-money-for-links-and-rather-give-out-an-iPod syndrome. It doesn’t matter.  Google is insanely interested in your intentions and you’re already doomed being an SEO. Your intention is to outsmart Google. Most of your links should be discounted by definition and the only reason they aren’t is because Google lacks the technical capabilities to do it properly and fairly.  

There is another reason why having links that you’ve paid for with real money is not that scary. Think for a moment about your link profile. If your links aren’t 100% natural  and Google could find a way to algorithmically discount those that have been built, do you think it would? Of course. It doesn’t do it because there is no way to determine the intention of a linker, unless in obvious situations (obvious spam or link networks).  

If paid links are done properly they are no easier to detect than links you’ve bartered for in a different way – given a reciprocal, a free piece of content (aka “guest post”) or an iPod  (aka “a competition”).    

Links in context  

Get links that are embedded in real articles. There are many reasons why search engines would prefer these kinds of links rather than footer/sidebar links not surrounded by context. They are harder to buy, harder to automatically insert on an array of websites and are more time consuming to build artificially.

So if you’re wondering why aren’t your sites ranking despite your link building, take a look at your link profile again and ask yourself:  

• how much of my link-building effort has gone into no-follow links?
• how many of my links are on pages that are well indexed?
• have I got links from power domains?
• how many strong links have I managed to obtain?
• where are they? In footers? In a site-wide blog roll? Or are they snuggled in a cuddly piece of content?

It’s not “build links and own”. Everybody builds links. Not everybody owns. Build links that matter.