A user of a wireless device, such as a mobile phone, can make purchases or obtain information via a network, such as the Internet, using both voice and non-verbal methods. Users can submit voice queries and receive non-verbal replies, submit non-verbal queries and receive voice replies, or perform similar operations that many the voice and data capabilities of modern mobile communication devices. The user may provide notification criteria indicating under what conditions a notification should be sent to the user's wireless device. When purchasing opportunities matching the selected notification criteria become available, the user is notified. The user can respond to the notification, and immediately take advantage of the purchasing opportunity if he so desires. Mixed-mode interactions can also be used by sellers to more advantageously control the marketing of distressed, time sensitive, or other merchandise/services.