Small Investment
Since most new ventures lack a ton of capital, finding the best usage of money on hand is important. Using Google Apps as a hosted solution is a smart idea because you've got to put up very little money to get started. When you need to get your computers up and running and it's essentially just you and a few email addresses, you can get just get started with ease and then worry about the rest later on.
Scalability
When you start out with Apps, you'll never to worry about where the roadmap is for expanding it because that's already been built in by Google. Both large and small companies already use Apps and it's been proven to work for organizations that are growing at a fast pace. You can use Apps as you start out, and it grows as your company does - making the investment to expand your software and productivity much cheaper in the process.
No IT Hardware
Do you know anything about running servers? How about connecting them up with firewalls and switches? How does that all connect up with the software that you use? If you don't know the answers to these it doesn't matter these days. You can use Apps to get up and running with your data securely - in no time. You won't have to worry about where your data is and what could happen to it if something goes wrong.
Extensibility
When you start licensing Google Apps, you'll get access to some other great software in the cloud that can help you run your business over time. This can be found in the Google Apps Marketplace, an "App Store" of sorts for businesses. Whether you're thinking about a way to mass communicate with your customers and potential clients, need to manage a growing payroll or require a tool for project management, you can find these things in the Apps Marketplace.
Reduction of IT Support Needs
Often times growing businesses need to start worrying about having dedicated IT support personnel in order to take care of computer problems. Yet this issue is becoming a thing of the past when one decides to go with a hosted solution. Instead of having to worry about directly hiring someone with the technical "chops" to manage your computers and servers, you can just let Google do all the work for you. Seriously.
One of the great things about newly-formed businesses is there are often no preconceived notions about how things should be. That's a benefit that anything new has in that there is the opportunity to try something new and not worry about what may or may not have worked in the past. That's why there's an opportunity right from the start - right now - to implement your IT infrastructure around Google's services.