Coming Up with a new mention monitoring tool

The concept is simple: Tracking mentions worldwide for any given keyword or phrase. (Your company, brand, your competitor, keywords of a campaign, anything) The data is crawled from all the search engines, news websites, social media sites, blogs, forums, communities, review websites and video sites.

The launch plan is to give free subscription to 1000 users. And the platform will be closed for signups and it will be invite only. There is another option of submitting your details and we may approve you to be a free user.

But my question here is will this low end disruption model work? Do you guys use mention tool and if not, would you use a free one?