* Your pro package is too cheap. If you're in the DevOps market space, I'm willing to bet that 99.99% of your potential customers would be as willing to spend $10 per month as $1 per month. If you can demonstrate a savings of one man-hour of labor per month, you could probably charge $100/month without too much difficulty. * Your pro package is too expensive. As a recent guest to your site, the free and the pro plans look very similar in terms of benefits. Why should I go to the trouble of whipping out a credit card when I can be lazy and just use the free plan that looks almost as good? My guess is that you have a bunch of freeloaders who will never convert to paid either because they are cheap or they don't need any additional service. * It's not clear what the benefit of your system is to your users. On the front page of your site, you should have a clear explanation of how a customer's life would be better if they gave money to you. You're assuming that your entire audience not only knows what IFTTT is, but you're also creating a dependency on IFTTT to explain the benefits of your own product.
As a first shot, I'd try to think of the types of users who would benefit from using your product.
You could tier by many different characteristics - response time, monitors, types of reactions, monitoring intervals - even access to https. If you can break down your potential customer groups by willingness and ability to pay, you'll have a better idea as to which characteristic(s) should change from tier to tier.
I have a free chapter up on customer value that you might help - http://taprun.com/pricing