create a minimum viable product
By creating a product which is limited to its core functionality, you can verifying whether it provides an added value or not: if it does, you'll find paying customers for your MVP!
First, get some inspiration: find out how successful companies like Dropbox or Zappos have tested their initial offer. Get to know different MVP strategies.
A good help to find out whether customers would pay for your product or not, is to launch a Kickstarter campaign and get some pre-investment from strangers.
Indiegogo is a second well known crowdsourcing platform and very similar to Kickstarter - you might want to look in which portfolio your product better fits.
A letter of intent is a good way to get a strong signal (way stronger than a simple yes) about whether a customer is likely to sign up, once your product is ready.
Create a fictive Ad, linking to your landing page and describing your product - are customers interested and click on the Ad (or even sign up on your page)?
Similar to Google AdWords, facebook Ads can help you to test if there are customers out there who are interested in your solution.
Like ClickMeter, Linktrack allows you to create trackable links and meassure the customers actions.
If you're working with Google Analytics, the URL Builder from Google helps you to simply create trackable links and monitore them in your Google Analytics account.
Probably the easiest and fastest link tracker out there, post in your long link and directly get it shortened and ready to post and meassure.
A tool to create and track unique links. Distribute them to customer groups or use them in ads or campaigns to find out what is of most interest to customers.
Build a free landing page or website - choose from many templates or use the easy to use, drag and drop page editor.
A feature-rich website builder which lets you create your own website by dragging and dropping elements - choose from a lot of awesome templates.
Another great tool to create good loking and fully functional websites without prior coding skills.