This is a really good idea, and it would for sure pay off.. I work in SEO & Internet marketing, so I write for Search Engine rankings all the time.
Here are some of the top tactics we can use :
1. Use as many words in the Post Title as you are able.. Example "JW.org (Jehovah's Witness official Website Link) Watchtower.org"
2. The Title still needs to be relevant, to the posging, so don't use spam words.
3. The first 2 Sentences of the first post are the best place to insert additional keywords. You can repeat the words in the title here, example.. "Regarding The official link and website of Jehovah's Witnesses Watchtower Bible and Tract Society"
4. Make sure to insert Key Words regularly through tout the post, like "What is Watchtowers website" "org website for Jehovah's witness's" new world translation listen to online"
5. Using the same word over and over again, will not be effective. JW.org at the end of ALL posts wouldn't help, but if it was on some it would help.
6. When possible include links to other Relevant Posts on JWN into your post.. Like this http://www.jehovahs-witness.net/243317/1
7. Include Cities or States in your post, example "Bethel in Brooklyn New York"
8. link to other Relevant posts on other sites example - http://www.jwfacts.com/
9. Post links on other sites such as Ex JW Reddit linking to JWN or your post.