Monetization options - other than ads - for consumer SaaS

I started a consumer SaaS almost 2 months ago. It's a calories counter system. You log in, register your meals and the system tells you how many calories you ate and the type of those calories. You cannot eat more than 10% of red calories, more than 35% of yellow calories and green calories you can eat as much as you like. It's currently free. The system now has around 3.6K users with something around 15% really active users and it is growing at a rate of 100 new users a day.

Any ideas, besides ads, on how to monetize this system?

Consider adding some premium features that people can pay for, some ideas might be:
- SMS Alerts (they cost you money, so is a justifiable premium feature)
- iPhone App
- Ability to see average statistics from other users
- Include support

Basically it would turn you towards a freemium model, but it sounds like it could be successful for your type of venture.

Maybe look into amazon affiliates and linkshare? You can review/suggest books and products and get affiliate income.

To add: You should have a list and send these people a newsletter every so often. Offer informative tips on diet, exercise, etc and maybe some products or books here and there. The weight loss niche is one of the most profitable you can imagine. You can suggest ethical products to them that you feel will help them lose weight. I know clickbank informational weight loss information products convert very well, but you have to see which are truly informational.

Well if you have all their emails and hopefully you have them opted in to a newsletter, you can do a few things.

1. Every so often send them an affiliate offer where they sign up, or buy a product and you get payed a sales commission.
2. You can sort of lease the list to marketers, like ones who have created new products or are marketing products which may be very useful for your email list.
3. Congrats on getting your SAAS up! I want to make one eventually!

Basically you have a LOT of value in the email list itself, I forget how much but email lists convert like 40% more than blogs. You could just keep getting more and more users, then keep offering them stuff to help them with controlling their calories. Whether its an ebook, or a special device, or whatever, you can get a commission on those sales.

Here are a few ideas:

1) You can offer access to a private forum aka CalorieCountSystemPRO, and charge $5-10/month for access for the interested users to communicate with each other, share tips, meals, etc.

2) If you get demographic information for each user (age/sex/location), you can aggregate data into reports based on trends of what people e.g. 28/m/NYC are eating. These reports can be used to create interesting infographics or blog posts to drive traffic. OkCupid has done a great job with this: http://blog.okcupid.com/index.php/the-4-big-myths-of-profile-pictures/.

With enough data aggregation you could look into selling the findings/anonymized data.

3) Identify the users who commonly hit the calorie goals, analyze what they eat, and launch a hot new diet trend that rocks the world. A series of books, TV show, flavored water and branded meals follow.

Just a few options.

Is there a way to create a "Pay what you weigh option" or equivalent to motivate people to lose weight? I don't quite know how you'd make it work, but I think it's an interesting way to think about it.