A link exchange is a method of linking two sites together. Some link exchanges are frowned upon by search engines and others are fine. Before even considering link exchanges, make sure you've created a quality homepage and quality content. Read below to learn how to spot good and bad link opportunities.
How do I know a bad link exchange from a good link exchange?
Generally, treat a link exchange as an in-person referral. If you were a vet, would tell a customer about a pet store or chain of pet stores? Probably. If you were a vet, would you tell your customers about mortgage refinancing? Probably not. Here are some comparisons of good and badEdit Table... link exchanges:
Good Link Exchanges
Bad Link Exchanges
Are sites related to your topic
Are sites unrelated to your topic
Are editorially approved
Are a free-for-all, everyone gets a link
Are on high quality sites
Are on sites you can't imagine anyone visiting
Involve emailing or calling someone
Use a completely automated system
Are popular sites on or related to your topic
Are sites you've never heard of
How to participate on Good Link Exchanges
There are a few ways to become involved in a link or banner exchange.
One way is to email moderators of sites that are related to your wiki and request a link. Sometimes they will say yes, sometimes they will say no, and other times they'll require a link back (hence the world link-exchange). If they say yes, your work is done. If they require a link back, check to see if they have an image they want you to use for them (and see the tip on linking back below).
Often times you'll find sites that are willing to link to other sites on the same topic. Be ready to give them an image that is similar to what they have on their site. Also be prepared to tell them how they should consider linking to your site. If your site is a dog leash wiki, "Dog Leash Wiki" makes sense.
Linking back
Don't be afraid to build a page with links on your site and link to sites you approve of. Your users will appreciate image links and short descriptions with the links. The Anita Blake Wiki has a nice link page.
Advanced Tip: Download a free Google toolbar from SEO Tools that can help you determine how each site you are visiting is ranked (a sign from the search engines that they are trusted, relevant sites).