just create product page and 2 to 3 profile in some good social networking sites.Start gathering relevant user by posting your link discus and popular group. Ask them you join your page and make them stay tuned with you.
yes dear today social marketing is very popular media of marketing, it increases traffic to your site and help in getting higher rank.
I agree with indusharma, I have created profiles in social marketing and getting good traffic and page rank to the site, nowadays social marketing playing a good role in building the traffic for the sites.
You could also start talking about the problems that your software helps to dissolve. Remember that people join social networks not because they want to be sold to, rather they join them to talk with likeminded people. So find topics that people want to talk about that surround your software. For example if you have a software like Adobe Photoshop, you can talk about graphic design tips and tricks. You could try to demonstrate how your software solves a problem that people have and you instantly get people talking about it, meanwhile you are marketing the benefits of your software. Think about what kind of problems your target audience might have and then either create content around it on your social networks site or refer to the website that has a solution on it. Let me know if that helps
Social media is a good way to advertise software and other products. You just have to generate enough buzz in order to get people talking about your product, either by giving them a sample or a "taste" of your product or through any other way that would picque interest.
Create a Facebook Fan page. Invite your FB friends to it and encourage them to 'like' it. Use TwitterFeed (or, I think it's a native feature of FB/Twitter nowadays?) to cross-post between the two. Post regularly with awesome, interesting things that are share-worthy and that people are going to Like to their friends or retweet.
Social media sites are a great way for marketing.You can build a single page website which are very popluar these days.Create Accounts on social sites like twitter, Digg, Stumble upon, Facebook and share and add link of Your website there.It will help to increase traffic to your website and a goog name to your business as well.