Advertisements are shown to users when the queue underflows to avoid video stalls in players/plugins so users see minimum disruption in video quality. The advertisements are pre-fetched and cached at the mobile phone to schedule them during queue underflows. If there is no congestion in the network, the queue does no underflow and advertisements are shown only to meet ad contracts. During network congestion or disruption, the queue might underflow and specific advertisements are shown to equalize network unavailability until sufficient video data has been received.