For a website to become popular, you can't just do things "outside" of your site, but must also concentrate "inside" your site.
What I mean is... you can do all the suggested ideas like backlinking, getting other sites to link to you, getting added in link directories, search directories, manual submission, etc, etc.... but if you do not focus on your own site, and making it such that people who see it will want to return, then your efforts will not be rewarded.
For a website to be "popular" you need "return traffic". You will only get that if there is a reason for people to return.
Do you consistently update the content within your website?
Does the info available in your website change?
Is there anything new that you put on your website? How often?
I realize this can be hard if you are selling one product (I have no idea if you are or not).... but you can still keep the content fresh.
If your website has information that changes often, then people may be motivated to return.... if you have something they want. Google has fresh new search results everytime someone searches. They also have a service people use.
So once your website is such that you either keep fresh new content on your site (and change it often), or you have a service that people will want to continue to use.... OR have a product to sell that is good enough that customers will recommend you to their peers.... then it's all about trying to get people to "come back" and not so much getting people to "see you for the first time".
Ask yourself this.... of the millions of people that visit google daily, how many do you think are visiting google for the first time? Not many. It's all about return traffic.
Hope this helps