How about 'getting the word out' by talking about your startup and app on podcasts. You can start with my daily show called The App Guy Podcast. Subscribe On iTunes
https://itunes.apple.com/podcast/the-app-guy/id771670010?mt=2 then contact me through my website http://TheAppGuy.co

"I am the head of sales for a new start up "App". What is the best way to get the word out? This question has no further details."

Going out on a limb here but I feel like sharing some details about your app (what it does, who cares, etc) when you're asking questions about how to get the word out about it might actually be a good place to start vis a vis how to get word out about it.....

What is it?!

You can go for big PR, but that's generally only great for spikes of traffic.

Focus on who your customer is. Determine where they spend their time (online and offline). Then, create advertising and marketing campaigns based on their interests and where they spend their time.

In the beginning to have to grind it out. Figure out who your audience is and go spend time with them. Leverage your network. Ask friends, family, previous co-workers, and professional networks. Give them enough details to know who it is that you are looking to talk to.

For example, if your app is for young professionals that are seeking employment after graduating for college, tell your network! Be specific. Ask for what you want.

"Hello {your friends name here}. I am looking to get in touch with {your detailed description of your ideal customer} who would benefit from {your value proposition}. Can you introduce me to anyone that may fit that description?"

The other thing you can do is provide an invitation opportunity. It is always easier for people to give out an invitation than to tell their friends to expect a sales call.

If you want to talk more about it, give me a call and we can talk about user acquisition methods.