How to get to million users in a short span?

For any start-up, getting a user base of million users is counted as a big achievement. For some it may be a break even situation and for others it may be the right time for pitching the product to investors to raise funding. It may take years for any start-up to get to the magic number of one million. Besides offering a quality product, start-ups need to work out SEO, SEM with a strong presence on various social media platforms. As the financial and human resources are limited for most of the start-ups so every small decision  can make and mar the future growth of the product.

Here are some quick tips from Adam Smith, the founder of  Xobni (Outlook add-in) and Drew Houston, the founder of  Dropbox on how to get from Zero to a Million Users.