Hello, I just registered and would have read many of the posts and think they are very informative. I have a websites and wondering if anyone could help me out in increasing sales (by better SEO, obviously). Any advice is greatly appreciated. Any recommendations on getting guaranteed placement companies that WORK and are not spammers is also appreciated.
Thanks,

Submitting your site in online free directories and regular updating blogs will give you the quality results.

Yes and never ever forget to make great contents worth reading and can be useful to visitors. They usually make you generate more regular visitors. And as much as possible, never copy.

Use google adwords, we can Increase Sales using the following ways
Google Adwords are increase your negative keywords
use the Placement Network and try out the Display Ad Builder.

There are many techniques to be followed to do SEO. Its actually a long process. You cannot see the result in short period of time. Search in Google you may find different topics regarding SEO. Analyze and implement those. After few days you'll come to know what is what...

Hire a seo freelancer
No serious company offers 100% guarantees those that ofer such thing are scamers amateurs or non ethical

Regards