TIPS and TRICKS
Link popularity
Based on what I've seen when I've analyzed top ranking pages in search engines, and on what many other search engine optimization experts have told me, link popularity (the amount of links other sites have pointing to your site) is becoming a more and more important factor when determining how high a site will rank on the results list.
Google paved the way for link popularity as a relevance factor (their algorithm uses link popularity as a major factor when ranking pages) and their success has not gone unnoticed among other engines. Altavista and Inktomi for example seem to be following this trend and are apparently decreasing the amount of attention they pay to the actual page submitted to them.
Instead, they are placing more and more weight to how many other sites are linking to the page, what kind of sites are they and what kind of text is located in/near the links. It seems that links from sites dealing with the same subject as you and links from very popular sites (such as human-edited directories like ODP and Yahoo) can help your ranking in the search engines, while links from low quality sites such as FFA's and other random link lists will often be ignored completely.
This change of policy by some major engines is probably caused by the massive amount of doorways and other worthless machine-generated pages that have been flooding their indexes. The logic is that pages other people think are valuable resources will often get linked by other webmasters, while pages that are of low quality or do not contain any information at all will not gain many links - thus, the Top10 places will be filled with sites people regard as useful.
I'm afraid that this change might make it even more difficult for small and new sites to make it to the top and favor big, high-traffic commercial sites, but only time will tell if this change is going to make things better or worse. But it's no use to complain or get depressed about changes in search engine policies - we're just going to have to live with them no matter what.
How to build your link popularity
The emphasis on link popularity makes two things even more important than what they have been. The first is, as always, content. Good content ensures that other webmasters link to your site just because they think it's a valuable resource to their visitors - giving you traffic from the links, and a boost in your search engine rating too! The second thing is reciprocal links. They will also have a "double effect", increasing your visitors from the links and from search engines. The more links you have pointing to your site, the better.
There are also some "link-share" services that are designed to boost your link popularity. The way they work is simple: Each member of a link-share program places a machine-generated page on his site and links to that page from his front page. The machine-generated page has links to all other sites participating in the program. Each member submits his machine-generated page to all search engines, and the result is that each member has a link to his site from everyone else.
These programs have produced some positive effects in the past, but many search engines now regard them as spam and some completely ban sites that participate in these programs. Additionally, given the current emphasis on links from similar sites by the search engines, they are in most cases completely useless or even harmful, which is why I would strongly recommend that you do not participate in them. Focus on creating good content and establishing reciprocal links instead.
When acquiring links by using FFA's, reciprocal links or any other methods, try to get your primary keywords into the link text. For example, getting someone to link me like this: A Promotion Guide - Free website promotion tutorial would be excellent for my search engine placement, because it would contain the two most important keyphrases for my site; 'promotion' and 'website promotion'.
On the other hand, a link such as this: click here to see a cool site wouldn't be as good, because it doesn't contain any words that are related to site promotion. You can aid this process by naming your site so that it contains at least one of your important keywords - people will often use the title of your site when linking to you.
In order for all these tricks to work, you must remember to submit any pages that link to your site to the search engines, unless they have already been submitted by the site owner. People will often link to your site without letting you know they have done so, so some will fall trough the cracks, but at least submit those you have knowledge of.
To check your link popularity, you can either visit the engines and check it from there, or you can use this free link popularity checker. It currently supports Google, MSN and Yahoo.