Notice I said 'simple concept' not 'simple process'. It is a lot of work to find sites that have a similar audience as yours, then search their site to see if they even offer free links to other sites, and then find contact information to ask them to link to you.
Here are the top 5 excuses I have heard for not getting linked:
1. It takes way too much time
2. For every five I ask, I'm lucky if one actually links me
3. The sites that link to me always seem to have low traffic
4. I never get more than a few visitors a day from these links
5. I hate having to give a reciprocal link
My responses to these excuses:
1. Spend 30 minutes a day and find as many places as you can. If you stay with it you will be amazed at how much you will have accomplished after a couple of months.
Some days you may only find one or two sites, but on others you will get lucky and find a place with dozens of resources listed. You can then just visit each of those and wipe out a large number at one time.
2. It is definitely a numbers game but if you don't ask you will never know if they would have linked to you or not. There are also many factors that can better your chances of getting a return link. I will go into more detail below.
3. Many times this will be the case because the sites with tremendous traffic usually want you to advertise with them or have equal traffic counts for a reciprocal linking arrangement.
Several points to keep in mind, though. First, some of these sites may not stay small forever, and as their traffic grows you will hopefully start to see more visits from them. The other thing to keep in mind is that if you stick with this you will end up with a couple hundred links in no time. If each site sends you only one visitor per day that is an additional couple hundred visitors that you didn't have before. And its free!
4. The answer here is basically the same as the last. Another benefit of these links is boosting your link popularity for search engine ranking.
5. Create a links page with links to other useful sites. Place your reciprocal links on that page. Don't bury the links page but offer it as just one more valuable piece of content for your visitors.
Some larger sites require a graphic or link on your main page to consider your request. I typically skip these and go to the next site, unless their link adds value to what I'm offering on my main page and if there is a good chance I'll get a great deal of additional traffic from them. You can try it out for awhile and if you aren't comfortable with the arrangement, just remove the graphic and let them know that they can re- move your link from their site. At least you have given it a try.
To look at it another way, if you sell advertising on your site you are sending away some of your visitors in exchange for money.
In a link exchange you might send away some of your visitors, but in return you are getting additional traffic to your site. Typically you would have to spend your own advertising dollars to get this traffic anyway, so it is the same as if you had an advertiser on your home page.
Besides, hopefully your site will be interesting enough to keep them around for awhile, and when they are done, then they will go and visit your links.
Now that we've covered the excuses, let's look at how you can increase your chances of getting linked from other sites.
First thing is that you really should have a quality site. Don't just throw together a page of banners and expect people that have worked very hard to get the hundreds of thousands of visitors to want to link to you. Your link adds no value to their site.
The next important item is to personalize your email to them. Actually take the time to visit their site and find something that you like about it. Find contact information and even a name if it is listed.
Find the specific category or page that you feel your site would fit well on and mention that page specifically in your email.
If they think your email is generic they'll delete it right away. I know I do. The latest fad is to use automated programs to create theme pages and blast out automatic emails to every site the program finds.
This may work to an extent but more than likely the only ones that really benefit from this are the creators. The search engines already know about this and have provisions to penalize sites using these.
They have quickly gone the way of the FFA pages, or the Dodo.
If you make an honest effort at this you can expect a decent return for your efforts. Look for shortcuts and your chances of huge success are shorted.
The next logical question in all of this is how in the world you find sites to link to you.
My favorite starting point is to find the sites that are linking to my competition. If they are willing to link to my competitor, they just might be willing to link to me too.