Advertising agencies losing out on data primacy

Interesting perspective highlighted in today's Financial Times that advertising agencies may be losing out to increasingly digital savvy clients and also no longer seen as having access to key sources of data.  According to the Council of Marketing, the key data for organisations in terms of marketing and advertising is now primarily in-house such as web site traffic.  This trend is leading major companies according to the story to build their own resources in-house, draw on specialist IT suppliers and cut back on traditional agencies.  Another element in the move from mass media to interactive media and changing influence of the promotional disciplines.