Other than that, I think the idea is straight forward and decently presented. I would like you to highlight on that front page what makes you different (read: exceptional) than other providers.
My aim is to provide more data analysis than other monitoring sites and give you feedback on the performance of your web application.
I have signed up and am testing it out, so far it looks very easy to use. I do like the visualization with Google Maps to get various response times. Very impressive.
In my setup I made a public service where external tools can retrieve some realtime stats like current number of users, queue lengths, number of jobs processing etc. Pingdom uses this service in different custom checks and it kinda works, but I can't use the stats or graphs for anything. Not all checks should be described in a status code and response time - a simple number would be great. Make graphs with that and allow users to set a threshold for when alerts should be sent.
Another thing missing is support for basic authentication.
As others have noted your front page is not really getting the message through.
Fx. I have a service here: http://api.convert.io/realtime.svc/pingdom/queue-length which prints out: <pingdom_http_custom_check><status>OK</status><response_time>2</response_time></pingdom_http_custom_check>
How about you offer the same, but add a few more check types. One with the status/response time and another with just a single number.
<nimbu_http_custom_check><check_value>2</check_value></nimbu_http_custom_check>
After three sites, I was told I needed to upgrade. Clicking said link did nothing. But can still add sites by going to http://nimbu.net/addresses/new; an error is presented, but the site is added anyway.
Calling redirects failed is problematic; for example, try monitoring http://www.google.com/ The non-US pingers will always fail due to country redirects. And http://www.google.com/ncr won't work either, because it always redirects.
Nimbu reserves the right to use your name and/or company name as a reference for marketing or promotional purposes on the Nimbu.com website and other communication with existing or potential Nimbu customers. To decline Nimbu this right you need to email help@nimbu.net stating that you do not wish to be used as a reference."
This is completely unreasonable. You want me to email you to decline the right! You should have to _ask_ ME for the right!
Also, one feature I myself would pay money for is sha256 validation of the content of specified files (html, js etc). Since I'm using AJAX I don't really have a problem with dynamic content. I want to be notified when/if my site is defaced. I will pay $5/month and consider it a real bargain, if you have multiple monitoring locations to make it hard for defacers to serve selective content.
The content validation idea is very good thanks.
If not, you should make that clearer too. When I think of site monitor, what I want is to be able to monitor my hdd, cpu usage, ram spikes, main domains, etc. E.g. similar to serverdensity.com's offering.
Add some more info about exactly what you offer, and the cost. I know it says free on the sign-up page, but you should make it clear on the main page that this is a beta period.
Good job on actually launching though. Many people don't even make it that far!
It would be good to understand the location of the server(s) doing the monitoring.
The unique aspect of this product is the individual analysis of data and suggestions/alerts before your site goes down. It will warn you if things suddenly change on your site, something that I don't think any other sites do.
