Regardless of your specific business, if you are just starting a business, getting your web presence up and running as quickly as possible can be a tremendous asset to your success. Yet, how you spend your money early in the business is especially critical... especially when that money is limited.
Your web presence can serve many purposes... information, sales, building credibility, attracting visitors through search, etc. But some of this takes time, which is why it is good to start building traffic to your site as soon as you can.
This may also be important regarding other expenses. Especially in the early days of a business, as things are developing, printing a lot of marketing materials when information about your company or product or service offerings may change, can be a costly waste. Even if printing these materials early on is critical, you'll want to maximize their impact by getting your website URL and email information on them immediately.