We rather thought it to be a maxim of advertising that if one is promoting a new technology that could render unsophisticated potential customers nervous, one should make one’s ads as reassuring as possible: many people are convinced that it’s all them satellites wots mucking up the wevver for example – so was it really wise of Rupert Murdoch’s evidently relentlessly downmarket Sky TV satellite channel to use an exploding television set as the punchline of its commercial?