It is common today for stores and offices to provide free Internet Access by WiFi. This would seem a nice courtesy item, but many are improperly configured and installed, posing a security risk to both customers and the business. Many are not encrypted for simplicity of use. This could mean that someone sitting at the next table could be monitoring the traffic. Many will say that this isn’t important, but how important are your passwords?
The next issue is not isolating the guest access from the Local Area Network properly. This can provide a means for accessing servers, capturing data, or sabotaging the system. Guests should not be able to scan or access other network devices.
A properly set up guest access point will allow you to offer the service while minimizing the risk.