The advent of Blu-ray technology has not managed to offset the downturn in sales of DVDs, according to market researchers Screen Digest and reported in today's (Thursday) London Financial Times . In fact, according to the Screen Digest study, sales of Blu-ray discs "barely made a dent in The Missing revenue" last year Helen Davis Jayalath, a senior analyst at Screen Digest, said that given the current economic climate, "we don't expect Blu-ray to be driving even minimal sector growth until 2010.