Yes search engines are a great way to get your site or product promoted. I have been doing this for a long time, and all of your suggestions are great. I would like to keep hearing more. Thanks for all your idea's
I write articles, 1-3 each day. It works quite well but is somewhat labor intensive. Forums (like this one) have also been effective.
I saw some very interesting marketing methods in this thread. There is obviously one main factor the affect your marketing methods choice, and that is MONEY. Do you want to spend money on your marketing campaigns or not ? If you want and you can, than PPC is probably still the most effective and fattest way of driving a good amount of traffic into your website. In the other hand if you don't have money to spare for advertising or you just don't want to spend any money, then forum posting, blogs and articles writing are a excellent ways to start building your website traffic. Its not as fast as PPC but can be at least as effective. In the past I've done some PPC marketing and made quite some money with it. The problem with PPC advertising is that you need to keep re-investing to make more money otherwise your income will just "disappear". With content writing you also can't just stop but it can become more effective and profitable in a long term project. So I guess that it all depends of your resources and I'm not referring only to financial resources