Its a fair question and one that people ask all the time, but that might be because you're thinking of satellite NBN. But unlike NBN there is no need to setup, install and point a monster satellite dish - instead exactly the opposite. The EcoSAT GOLD and EcoSAT BASIC include everything you need already inside the box - no need to add anything.
Also unlike the NBN we are not trying to download large videos, images or your favorite songs. Each burst of data is so small by today's standards that it isn't funny. But in reality that's all we need to get the job done. By reducing each block of data to only the bare essentials the reliability increases. Just a water level, its location and few other bits and pieces and its amazing how useful it can be.
It is also important to think about what's critical when it comes to remote monitoring. Often people begin by looking at cameras to monitor their stock, but then quickly realize that its hard to know exactly how much water you have from an image. Not only that, but when the tank hits the bottom, the only way to find out using a camera is to check the pictures, and when did you do that last? Its human nature to stop looking at something that rarely changes and then the one day things go drastically wrong we've forgotten to check it. We've all been there. The benefit of a sensor is that you can set the limit where you would like to be notified.
In addition to this if you know the exact level, then you can add a pump or generator to the system and automate the whole setup! Doing that with a camera is almost impossible.
Having said that though, cameras certainly have their place. An image is definitely worth 1000 words and sometimes there are situations that could only be explained by an image. Such as this one....