Why should my site exchange links?
Links to your site and from your site is a determinant factor (but not the only one) of the "relevance" of your site towards search engines. By "relevance" of a site, I mean that search engines have a way to determine the importance of a site just by "looking" at it. In Google terminology, the relevance of the site is called PageRank, and it is given by a complex algorithm created by the founders of Google that permanently crawls the web, takes a look at your site, follows the links from it and to it, and combining with a complex analyses of the text and META TAGS inside your pages, will determine its relevance. The more relevant your site will be, the more well located it will on a search result. Take a look at http://www.google.com/technology/index.html for more information, on Google's methods.
Each search engine applies a different algorithm to determine the relevance of your site, and no one knows exactly how these algorithms work. Only one thing is certain: you cannot finance the search engine to make your relevance get bigger, so everybody at first gets the same chances. The rest is made by guessing. Trying to change the META tag, title, site description, and keywords might result in loss or gain of relevance towards search engines, or might be insignificant.
Link exchange methods
Hand made exchange
One thing seems for sure, if you link and back link your site to many places, this will increase your relevance. It's like in real life; when you are at MacDonalds (just to state a company known almost all over the world), you see their logotype all over the place hundreds of times. In internet, it's the same; if your logotype (your link in this case) appears all over the place, then you will be very well known. It will increase your hits (people visiting other sites might follow these links), and consequently also increase your relevance towards search engines.
But you can't do this blindly. Putting links in places that are not in concordance to your content might not produce any effects, but slightly to increase your site visits. It's normal, MacDonalds do not advertise outside of their area of relevance. That way, it would be more beneficial to select carefully those who you want to trade links with. It is also important to respect some sense of ethic. Some search engines might ban you if you link to non-ethical information support or illegal site content. After this, you just have to browse the net and find sites that are related to yours and begin to exchange mails with the webmaster to see if they are interested in placing a link at your site on the condition of you placing a link on your page to their site.
You can now see the amount of work in front of you!
Once you have dealt with the quality of the links, you should take in consideration the technology used to display the links and the technology your partners will use to display yours. It is important that the spiders that are crawling the web can read the entire public structure of your site and find the links that you want to use for relevance. There's no use to have a page called links.htm linked to no other page of your site. This page won't be crawled. Your links should also be put in the most simplest way, meaning HTML into an HTML file. Certain spiders are unable to follow links that are code-generated by PHP, ASP, or as the result of AJAX programming. Google recommends to use a text browser to check a page, like Lynx, because it is the way the spider will crawl it. Check Google's webmaster guidelines for more information.
This description is obviously not exhaustive; I'm in the middle of the process of learning how to do it. But you might have in mind that this is a very thorough and long process. No pages are ranked 5 the first day! Also keep in mind that what you have changed might be reflected on search engines only days after. In that sense, Google gives free tools that helps people to check on spiders information on their pages. They tell the date of last checking, for instance.
Automated scripts and programming
This method consists of some scripts, installed on your site, with administrator and public functionalities that cut on the work of contacting unknown webmasters. By installing their scripts on your site and pages, you are saying to all others that you are available for exchange within certain categories and areas. The only task you have to do then is contacting already identified and targeted people of the program and adding their links when they add yours. The control in time of the validity and reliability of these links are however difficult to manage. It requires a long term time investment and generates a lot of broken links in the internet.
Link exchange programs, like those existing in the net
By registering yourself in one of those programs that are flourishing through internet, you will facilitate your life a bit more. These companies propose you an amount of site already willing to participate in the process of exchanging links. Every member of the program is checked previous to inscription for ethical matters, and categorized in the appropriate grouping. As a webmaster, you will have to manage your link page the same way as before, but the long term management will be guaranteed by the company who will inform you of broken links, avoiding the site from irrelevant categories to yours to contact you for linking, etc.
The problem with this method is that however you find free resources on the internet, most are locked to simplified functionalities. The free one I'm using prevents me to ask more than 5 links a day. If I want more, I would have to pay a fee that I'm not ready to pay for a hobby activity. It is also time demanding since I have to build the link page every time someone accepts to link to me or every time someone requests to link to me and I've accepted.
General drawbacks of existing solutions and a solution proposal
Well, depending on what people want to achieve in terms of link exchange and depending on the complexity of the technology used, many solutions exist. I have presented here three of them: manual, automated, using a third party. Other solutions might exist; however, what I have observed on these three is that none cuts on the works of the webmaster. This is a repetitive and daily work, that in my perspective serves only to:
- Guaranty the quality of his links, adding new or removing old
- Find new relevant links
I've also observed that they are in the same link exchange programs, very few webmasters are available to answer my requests for link exchange.
Let me bring a new idea by asking a question: Why don't we take the problem to the other side?
Let the third party analyse what is relevant to who, let the third party categorize the links and check the ethic and legal part of the site content, and finally let the webmaster link to everybody inside the same category by default, allowing him eventually to remove those very few links he doesn't require.
That way, every new webmaster registering a category would automatically add his link to your page if in the same category, at once, with no manual intervention, unless, for some reason, you decide not to link to him.
- The webmaster cuts on time spent to add links to his link page, since the link page is generated automatically by the third party based on the content of his categories, plus what he chose to add, minus what he chose to remove (this part involves dynamic page consulting on the server of the third party, but I'm confident that spiders would follow these links, as sure as they follow in-site dynamic links).
- The webmaster has his link pages built since the very first day, and his work consists only in removing those few he doesn't want and adding those from other categories he wishes to add.
- The third party verifies, in real time, the validity of the links, and avoids broken links at once.
I hope you might give some opinion on the matter. Like I've said, my experience on the topic is very limited, and everyone is welcome to participate and contribute by registering comments. Based on your optimistic answer, I will develop a PHP solution for the purpose.
How can I see where I am linking to, and who links to me?
There's a tool that many SEO sites are using to check links and back links. It consists of a Perl script that determines your popularity on search engines, by counting links to your page. You will notice that you won't find there every site that is linking to yours, but only those identified by the search engine. For example: http://www.submitexpress.com/linkpop/.
You can also see who you are linking to by using a common META tag analyzer that would give you an idea of what a spider can see from your page. For example: http://www.submitexpress.com/analyzer/.