That seems like an aggressive goal, but I'll assume that you have created a product that offers significant advantages over existing solutions and that the total market size is much larger than your 5-10K target.

An excellent starting point for a subscription-based technology product is the book Hooked by Nir Eyal. He analyzes how apps like Instagram grew rapidly despite the existence of many other photo sharing apps. Check out his Hook Model and see if you can apply it in your situation.

Ensure your website is optimized for conversion. That will maximize the yield you get from your SEO, SEM, ads, and other expensive activities.

A freemium model has been proven to work to get lots of subscribers quickly, but you'll have to plan your feature list carefully to deliver great value in the free product but make the upgrade to paid status enticing. Buffer, Evernote, and others do a great job of this.

If you are budget-constrained, creating brilliant content that's relevant to your potential users might be cost-effective. But, it's not going to work overnight. With a big "results not typical" disclaimer, I'll offer an example of how this could work: http://www.movoto.com/blog/movoto-com/buzzfeed-for-real-estate/

Good luck!