A method of delivering video content to a client device from a server, said video content comprising a sequence of segments and wherein each of the segments is encoded at a plurality of bit rates, said method comprising: a) receiving information at the client device about each segment, wherein the information comprises the bit rates, the duration, and a viewer importance parameter associated with each segment; b) identifying a first segment from the sequence of segments for delivery; c) calculating the time available to download said first segment, using the duration of the video content buffered at the client device, the duration of said first segment, and the minimum buffer duration to avoid buffer underflow; d) identifying a further segment after the first segment from the sequence of segments, wherein the further segment has an associated viewer importance parameter that is higher than the viewer importance parameter associated with the first segment; e) estimating the network bit rate between the server and client device; f) establishing a proportion of the network bit rate to make available for delivery of the identified further segment, thereby establishing the bit rate to be used for a concurrent download; g) determining a maximum segment bit rate in dependence on the estimated network bit rate minus the bit rate to be used for concurrent download, on the duration of said first segment, and on the time available to download said first segment; h) identifying and selecting a bit rate for the first segment that is no greater than said maximum segment bit rate; i) identifying and selecting a bit rate for the further segment; j) delivering the identified first segment concurrently with the identified further segment to the client device; whereby, when the viewer importance parameter associated with said further segment is higher than the viewer importance parameter associated with the first segment, the identified bit rate is higher for the further segment than for said first segment. a) receiving information at the client device about each segment, wherein the information comprises the bit rates, the duration, and a viewer importance parameter associated with each segment; b) identifying a first segment from the sequence of segments for delivery; c) calculating the time available to download said first segment, using the duration of the video content buffered at the client device, the duration of said first segment, and the minimum buffer duration to avoid buffer underflow; d) identifying a further segment after the first segment from the sequence of segments, wherein the further segment has an associated viewer importance parameter that is higher than the viewer importance parameter associated with the first segment; e) estimating the network bit rate between the server and client device; f) establishing a proportion of the network bit rate to make available for delivery of the identified further segment, thereby establishing the bit rate to be used for a concurrent download; g) determining a maximum segment bit rate in dependence on the estimated network bit rate minus the bit rate to be used for concurrent download, on the duration of said first segment, and on the time available to download said first segment; h) identifying and selecting a bit rate for the first segment that is no greater than said maximum segment bit rate; i) identifying and selecting a bit rate for the further segment; j) delivering the identified first segment concurrently with the identified further segment to the client device;