First off, the major engines like Google (tm) for example:
Will only show you backlinks of X ranking. Anything less, wont show up if you put in the standard link:http://mysite.com. This will net you a fairly small result as a matter of fact. Now if you put in the same thing, with one slight change link:mysite.com, no http etc etc.. the results generally expand considerably, as much as 3 to 5 times or more. Further, if I were to ask this way link:http://www.mysite.com .. I would get yet another result.
The same is true for most of the major engines. Recent algorithmic changes, made some sites backlinks appear to drop nearly off the board, when in fact, most of them raised up with the new results, if you query the engine for all the variations of your site url, you will find them.
Now, why do this ?
One, you have no control over how other sites, engines, blogs etc. link to your site pages. They do not all use the same url format. So to get an accurate picture of who is really linking to you, you need to use all the possible formats, as well as run a check for your entire domain. This will net you results for those who have deep linked into the site.
Ok, why ?
As noted, not everyone links to your site the same way, so variables have to be considered. However, the main reason is, the engines themselves are trying to avoid webmasters from knowing the exact numbers.
You might ask yourself why would they want to do such a thing ? The answer is a simple one, they don't want to give out too much information to SEO's. This is accepted by most SEO's to be a deliberate act on the part of the engines, particularity given the fact, that as little as a year ago, you could and did get, vastly larger numbers from the engines themselves.
Yahoo (tm) is bit more accurate, but not entirely, so again you are playing a guessing game, unless you understand, you have to query it through a variety of sources, in order to get accurate information. MSN, at the moment wont even give out that information :) and so it goes.
Ok, so how do you find out ?
Google (tm) webmaster tools:
Sign up for an account, and you will
find all kinds of details out about your site, including a much more accurate
look at its back link situation.
On the webmaster tools, you can get a decent look at some real time stats on who is linking to what pages. The results you will see, will be far different than what you might see, if you query the engine itself.
Yahoo (tm) has a similar account, and
background information provider.
There are tons of these on the web,
with variable results, but query several of them, and you can get a better
idea in some cases of your backlinks, than just the results off the engines
Ways to look, on the engine's themselves, these can be used with or without the www extension, and with and without the trailing /
link:mysite.com ( will give you a limited set of backlinks, generally above a certain PR rank and ignore others )
link: mysite.com. ( notice the space between the link: and the domain name, you may find the report can double or more, using this tactic alone)
link:http://mysite.com ( for main backlinks )
link:http://www.mysite.com ( for main backlinks )
+link:http://www.mysite.com ( the + here means it will give you all your site pages and outside links )
title:"Name of your site" ( Which may find references where there is no active link, but your site is mentioned. )
url: keyword ( meaning any url with your main keyword in it )
site:mysite.com ( which gives you all the pages of your own site the engine has indexed )
info:mysite.com ( which gives you details the engines have about your site )
cache:mysite.com ( which will show you the most recent cache the engine has, a good idea to see when they crawled it last )
linkdomain:mysite.com ( all links to that domain )
Now, not all of these will work on every
engine, as a few are engine specific, but most will work, and will provide
you with a slightly better picture of your real back link situation, than
the very first one alone will do.
Keyword ranking VS page ranking:
This is a very specific form of rank checking, and by and large one of the most important. Your overall site rank, can and will flex, given the number of backlinks and other factors that are outside of your direct control. Keyword ranking however, you have a bit more control over, and gives you a better image of how your site is doing.
Keywords are the backbone of the search engines. Where you show up for your major keywords, is more important than what your over all page ranking is. Your overall ranking in fact, is almost irrelevant, if you place well for your major keywords.
For example: If you place first page in the results for any or all of the major keywords that a viewer might use to find a site of your type, then what your site ranks over all page by page, becomes a useless number. As you could rank at 0 for your pages, and still come up on that first page of the results, if your site is well optimized for those words.
Everyone has seen this, and gone huh ? A site with no "rank" at all, and they are top of the chart. Most think it means they brought their way in, not necessarily so, it is possible to have a site page with no rank whatsoever, but that is well keyworded, and have it place at the top of the charts for that keyword. Mind you, if the page has good rank and good keywords, this situation is much more likely to occur.
A word of warning :
Some SEO companies use this fact to "promise" you top ranking on the engines. How they do this, is pull some uncommon word out of your text and can there by "prove" to you, that their efforts brought you top rank. Fact of the matter is, if your site has good density for keywords over all, and some rank, you would find that you already placed for those words to start with. So beware of this kind of "proof".
If you do not place well for your "important" keywords, placing well for your company name for example, is misleading. It looks good, but in point of fact, it's meaningless, unless you are a major player and your company name "is" a common search term. This does not happen very often. Search terms are common words in most cases, not company names.
This is called vanity searching. Try it, put in your company name, and very likely, unless you have a very commonly used name, you will come up on top of the results. The same is true if you put in your proper name ( it's amazing how much information you can get on just your first and last name ). However, again, unless your brand name, or company name, is a "household" word, it's not likely to be used as a search term, so ranking well for such words, is basically useless for most sites.
Do not use the toolbars as an accurate reference:
Many engines provide toolbars, that are supposed to give you a sites ranking etc. Well, they are, by and large a sorry disappointment in that they are seldom accurate. Statistics show, they can be off as much as 2 to 3 ranking points, so as a ranking checker, they are entirely misleading.
This is another one that is very misleading,
in that the rank in this case, is the number of people who use the Alexa
toolbar, who vista your site. So understand, the number you see, is a percentage
of the net population, that happens to use Alexas toolbar, it is not
an accurate number of visitors to your site over all.
Tracking your backlinks, using any of the above, remember, you are using a tool, a tool that gives an indication of possible success, they are not the "be all and end all" of predictors for the sites possible viewer base. Many many factors go into that mix, your "rank" and backlinks, are only a few of them.