Is SEO Effective ?

yes and no...if you are optimizing for terms that won't convert for you, whether too generic or the wrong specific ones you will be missing out. When done properly, with onpage, offpage, and research into what keywords to choose, then you have a very powerful mix where SEO does extremely well.

Yes SEO is very effective. It gives you FREE traffic from popular search engines like Google, Yahoo and etc. However, to get top position on your target keywords, you have to invest more on SEO. As far as I know, there are many guys do outsourcing SEO to some developing countries like India, Philippines and so on. I think, via doing this, they reduce cost as well as save their time too.

Yes, it is very effective if you know what you are doing. One thing know one mentioned, it is FREE traffic!

I can say SEO is the only way to get traffic anf promote your business world wide too.

Yes Seo is effective method to increase you business online.

SEO is the basic and the starter needed for a site.. SEO based site gives good traffic and indexed soon in search engines..

SEO is absolutely effective and it is a great way to be found. But you also need to offer what and why people need to visit your site. Like unique content, user friendly navigation..

SEO is a big decision that can potentially improve your site and save time

Sure. SEO is very effictive tool to increase the page rank.