The way the license information is presented is a little misleading. The Community edition is described as for 'Open Source & Hobby Projects', giving the impression that its not possible to release a commercial product using that. Thats not true of course, its LGPL licensed and so can be used for commercial software as long as the license obligations are adherred to.
The desktop app I sell uses Qt, against the LGPL license. I would probably pay for the commercial license from them if it was more reasonably priced, but $295 per month to distribute on Mac and Windows is just too much to swallow.
Roughly: link dynamically or provide object files for relinking; don't prohibit reverse engineering of your software (for compatibility with new library versions); don't modify the LGPLed library to require a proprietary component to function.
Why would someone need/want to use Qt by not dynamically linking the library. I've never understood Qt's business model or what I can and cannot do with it. I just use pyside on my pet projects.
The desktop app I sell uses Qt, against the LGPL license. I would probably pay for the commercial license from them if it was more reasonably priced, but $295 per month to distribute on Mac and Windows is just too much to swallow.