Yours is a Geo location based app, I understand.

There are many ways to penetrate your market. First, you need to segment your market into different verticals on the basis of the factors like age, interests, gender or location.

Once they are segregated, you have to design specific marketing campaigns catering to each category, focusing on number of sign ups and a great experience.

Such campaigns can be run both online and offline.

This would gain you both PR and aggressive Sign ups.

Don't follow anyone, make your own story. All the best!

In case you need help making the campaigns and measuring the ROI, feel free to get in touch. :)