Fixed wireless should definitely a part of any small/start-up ISP plan. If you're in an area that's solidly served by GPON and ADSL2+/VDSL2 by the ILEC phone company (FIOS), and they're really built the fiber network out a lot, that's hard to compete with. And hard to compete with a solid DOCSIS3 network that reaches everyone. You'd have to find an area on the far outlying reaches of your metro area that is much worse off, where a market need exists.