[Angel-Wings]

Another point - it's kinda useless to encrypt scripts - for all of the known encoders also decoders exist and since PHP's source is available, it's possible to modify it that instead of parsing the plain code comes out.
At all - the money these encoders cost isn't well spent, it won't keep the "bad guys" out so using them gives just some kind of a fake protection.
A good license is maybe better, either people care about the license, then you won't need an encoder or they don't care, for the second group of people an encoder isn't a huge problem, maybe just a small one finding the right decoder but that's it.

Personally - in a world of injections, XSS flaws and these problems I wouldn't install and run a "binary only" script on a production system for simple security reasons and other reasons already posted - like a stopped development.