It all depends on what you are selling the market you are selling to.

Word of mouth is powerful but it's dependant on factors like how long the job turnaround is and how often people are looking for that product/service.

For instance if you are selling mobile phone covers you are talking turnaround times of around 24hrs and a high frequency of buyers so word of mouth comments travel faster.

But if you are providing a service such as handmaking violins then the turnaround time can be months and the buying frequency low. So word of mouth can travel quite slowly.

However word of mouth does usually have less influence on the former than the latter.

Print advertising -is- expensive and very hard to measure any sort of conversion rate. Online advertising is, in comparison, a marketing revolution because you can measure the ROI directly. For example a banner link on this site could be tracked through the shopping cart of another site and you could actually see how many people clicked on the banner and purchased.

Press communications is a very powerful tool, it communicates to a wide audience and has a more positive feel to it than conventional advertising. So getting an article about your product/service in a magazine will give fantastic exposure but then you need to know how to deal with the press. Bare in mind that the press is online too now so there are oppotunities to get exposure on website articles.

Directories are a good route to go and are often free.