What are the best way to promote a business online?

Commitment and effort

Paid Traffic.
JV Affiliates.

You have free classifieds sites and Paid advertissemnts sites.
You have the network exchange sites you can join for free.

fresh content is only one way to promote a business...
i am a computer engg. and i have a company to connect with us regards to your computer related issue simply call at 0800-404-9205. you can ask question related to your website also like SEO promotion on that number .

Pay your affiliates a commission, give them good marketing tools, and you are all set to go!

you can use skype, add more people in contact list

My friend, apsense have great tools for that

Use a facebook page, run an advertisement on facebook. Post articles in forums.

social media is one of the best way to promote

One of the best idea of promotion is inter net , marketing of business.

I have a special suggestion for you. Just ask me this question on Skype!
My user ID is franto.hruz