Do They Have Quality Inbound Links?
You can tell a lot about a web site by the other sites that link to it. Typically, good sites are registered in some of the top directories like DMOZ or the Yahoo! Directory and have links from other good sites in their same industry.
You can do a ‘linkdomain:’ search on Yahoo! to view some of their best backlinks.
If they have been exchanging links with Viagra, casino, or other high-margin, off topic, cheesy web sites, then they are probably not a legitimate resource and are not a link source worth pursuing.
Does Their Site Offer Quality Content?
If search engines did not exist would you still want the link? Would it potentially send traffic? Do you enjoy their site? If the answer to these sort of questions is “yes”, then pursue. If the answer is “no” after “no”after “no”, then it is not a logical link opportunity.
Avoid the Sure Downfalls
Off the start you may be a little more desperate for links as you are learning SEO. A good tip is to stay away from drug, gambling, and porn sites as they obviously destroy your credibility. Other sites that link to those types of networks may also hurt your site as well (since they may eventually be penalized).
Always use your own judgment as you will be the one footing the bill if the idea is wrong.
Using Common Sense
That hemp/SEO store I mentioned earlier (one guy tried selling both from the same website) is a good example of not using common sense. If the site you are linking to has nothing to do with the topic of your site and no relation to what may interest your viewers, you probably do not want to link to them.
Carpet bomb linking strategies may be successful in the short term, but over time they will grow less and less useful to the point of ineffectiveness.
There is also an indirect linking effect to linking. If you link to really weird sites, then it lowers the odds that other industry resources will take you credibly or want to link to your site.
Example of a Junk Link Request
If you send junk link exchange requests like this, they will usually be deleted as spam. On the same token, if you receive a message like this, you should delete it as spam. Most link exchange requests should go right into the junk bin.
I was at your site today. Great site! I was wondering if you would want to exchange links. I already have a link to you located at http://www.spamsite.com/links/reciprical-linksexchange2/
As you well know, search engines look at links and give sites credit for their incoming links. By linking together we make both of our sites stronger.
Please link to me with the following information:
<a href="http://www.spamsite.com">Buy Viagra Cheap Phentermine
No Prescription Paxil Prozac Online</a>
Some of them even take it one step further and give you emails with subject lines like “your link “” final warning,” as though they offered any real value.
Eventually, Aggressive Promotion Techniques Get Discounted or Penalized
Even if a shady site has decent link popularity, you can usually bet that they will be losing it soon if they are associated with and exchange links with all kinds of random sites. Link exchange may work up until a point, and then eventually it becomes link farm. A link farm is a site with a bunch of completely unrelated links scattered about in no logical order.
Eventually, overly aggressive sites get penalized, but webmasters using those techniques will usually have already started another site, and you may end up suffering for their greed if you exchange links with incredibly aggressive sites.
Another trick they may use is to have you link into their good site and link to you from a different domain of essentially no value. Since their good site is not going to get penalized (because it does not link out to any shady sites), it does not matter much to them if their bad site and your site receive a spam penalty for being part of a link farm.