Whether it be a coffee shop, or a dental office, potential customers or business associates appreciate the ability to connect to the internet when accessible.  Offering a guest access point offers your business network more security, prevents malware infections, and helps your business appear more friendly and security-conscious. 

Secure Your Network

When you allow a user to log into your Wi-Fi network, you give them access to your network including network printers, any open shares on your network, unsecured devices on your network, etc. Though the majority of people are not going to compromise your network, and simply are looking to access the internet, setting up access for guests is still recommended to keep your network secure. A guest network allows users to use the internet through your Wi-Fi but limits access to your internal network.

Prevent Malware Infections

Devices that are infected can spread malware throughout a network via a Wi-Fi connection. Without a guest network, your network is vulnerable to any infected device that you allow to connect to your Wi-Fi. Having a separate wireless connection for guests keeps your network safe from malicious software through separation. **Not all routers offer this capability so check to see if yours does**

Be Courteous 

Though it is not expected or mandatory, when business associates or clients visit, offering a Wi-Fi connection is a nice courtesy.  When having guests log into guest access, this also strengthens the perception that your company is serious about security.