1. Poor or dated visual design
Nothing makes a customer say “no thanks” as quickly as a really gruesome home page. It could be horrendous colour choices or a naff logo. Or it could just be that things have aged badly. We sympathise a lot with businesses here because quality websites cost money; but things move quickly in the digital era. Sites that looked slicker than a brand-new Ferrari a few years ago now look like a third-hand Volvo.
State of the art… in 1997 (sorry Exmouth View Hotel, we're sure you are so much greater than your website!)
The simple answer is to refresh or start again. Yes, it costs money, but how much income might you be losing due to a duff website?