Marketing is a very important aspect of business which startups usually tend to ignore at the launching stage. It is true that startups have budget constraints and they can’t really concentrate on marketing at this stage. But there are some low cost tactics a startup can use for promotion and relationship maintenance – all online. Start by choosing a name that works; something simple, memorable and unambiguous. Then probably kick off a blog and not to forget keep checking the website traffic through some analytics. These tactics and suggestions are explained in further detail by the Startup Guru Dharmesh Shah:
http://onstartups.com/tabid/3339/bid/9008/Startup-Marketing-Tactical-Tips-From-The-Trenches.aspx

Probably the tactical steps don’t do much individually, but in aggregate they do start laying the foundation for much bigger things.

Find three closest competitors.  Pretend like someone is paying you $10,000 for locating each competitor.  Really try hard.  Barely managed to find three?  Take a lot of effort?  Great.  Now find 3 more.