I'm beginning to think more and more about viral marketing... By that, here's what I mean: Instead of working so hard to build links yourself that point back to your site, create a fun / unique / useful tool, app, game, etc... that is hosted on your site. Hopefully, people will like your tool / app / game, and naturally link to it. Here's my question... Has anyone tried this? Have you had any success? If I were to create something of real value, and people did start to link back to it naturally, how much benefit would that have for the rest of my site? What if the keywords for the tool itself weren't really all that related to the rest of my site? Would it still help the SERP's for the other pages on my site? I'd like to hear your general thoughts and experiences.