Why would people to link to me voluntarily?

Then hire a SEO professional to do the job if you have the budget. This would allow you to focus on content and other avenues of traffic generation (partnerships, offline promotions, etc).

PPC is nice, but even those that are making money with it are constantly working towards reducing their dependence on paid traffic. Regardless, the majority of people that use PPC miserably fail which is why a SEM pro's services can be very useful in setting up and managing PPC campaigns.

 

You have linked to sites before, right?

What made you link to it? then you have your answer

 

Affiliate Commissions

 

i did nothing not even one link i have not paid any and got PR2 on google
i think due to unique content or may be any other reason

 

Most of the answers here are going to be complete bull. Reminds me of that movie, field of dreams?, build it and they will come. Content is king, that has to be the most generic phrase for people that want others to think they are knowledgeable.

Try get someone to define "content is king", and then you will weed out the helpful posters from the bullshitters.

 

Agree with that...