Selling Service website, ~2.000 active users in trial period, never monetized, organic/incr.

Before going to flippa, tough to try here, maybe someone will be interested.
Only serious buyers please.

Site is actually complete online software-as-service, huge market.

Facts:
- site is live 13 months
- developed 6 months before start
- 2.000 members in trial period, all from organic traffic (about 50% conversion rate, every 2nd user who come from search engine opens account)
- traffic increasing 10-15% monthly
- all traffic / conversions in trial users are 100% targeted
- payments,packages, everything implemented but due to promo reasons never forced, so everybody uses service in trial "free" mode
- there is strong competition, but site is on most important keywords on first G page
- mostly of users are from US/UK/CA
- works perfect on simple shared host (I am using $12 or something monthly hosting package, and with 100+ users simultaneously no problems, because everything is coded to works fast, light, everything is in ajax, so also no even significant bandwidth spent...)

I am working on something else more than 2 years ago, and wanted few months ago to start forcing existing users to go to paid plans, + to remove "trial" / free plan for new users, but always wanted a bit more promo with free package.

All existing users are potential customers. Site offer 3 different packages of service, everything is implemented and ready to go as I said.

If I get fair offer I will sell (need money for another project) if I don't get nice offer I will not sell.

In this moment, with existing user base and 10-15 new users every day without cent spent in advertising and traffic, some monthly earning estimation is about $1.000, maybe $1.500.

If you are interested and serious buyer, PM for more details (URL, details, stats, etc)
Also if have any other questions feel free to ask.