Deb, please have a look at Wikipedia's conflict of interest guideline. I believe that webmasters should be able to do whatever they want with their own sites, but when they visit somebody else's Web 2.0 site, they need to follow house rules. Breaking the rules when you are a guest in somebody else's house is rude.
Link building is great, but you need to keep reputation management in mind. Wikipedia's rules strongly discourage self-serving edits. If you get caught, you and your client could suffer public embarrassment. We all know how well Wikipedia pages rank. Before taking this risk, I recommend reading this essay.
I also recommend you take the time to submit to the Open Directory Project, pay for a Yahoo! Directory listing (especially if the site is new) and look for submission opportunities at Wikipedia. Yes I know the Wikipedia uses nofollow on their links rendering them virtually useless from a link popularity standpoint, but—the traffic you'd get from those links is worth it. If you can find an opportunity to add your site where it will make a useful contribution, do it.
Which shouldn’t have been hard for me since I spent many years as a DMOZ editor. But the two entities are very different so I found that didn’t help much in the end.
To get started, I clicked the conflict of interest link the poster provided and read through the page, then subsequent pages and even more pages after that. After all the reading and link skipping I came away with two conclusions: There isn’t a page in the guidelines and the site itself that doesn’t warn (in some fashion) about spamming. Every page mentions it so unless you’re a total idiot, that should be clear .
Second, after it was all read and done, I still don’t agree with the logic behind the posters comments -or- understand how my comments could be construed as a conflict of interest. Even the conflict of interest guidelinepage I was pointed to had an exception " Merely participating in or having professional expertise in a subject is not, by itself, a conflict of interest"
I say "sincerely" because based on what I read, the guidelines provide a lot of positive encouragement and suggest editors approach the submission process with an assumption of good faith. The idea of submitting with a neutral point of view comes up over and over as does the issue of respect and consensus. All positive and constructive guidelines, and all related to my suggestion of making a “useful contribution”.
So why is it not right to add a site you own/are passionate about or add to a discussion and cite a resource you are associated with? Not everyone is trying to game Wikipedia. I can’t speak for others or what’s happened in the past but I do feel suggesting that someone is being rude or could suffer public embarrassment by contributing usefully totally goes against what they talk about here in common sense: “Being too wrapped up in rules can cause you to lose perspective”.