Apt Data Services Ltd, which publishes Computergram and a string of other newsletters and magazines, wouldn’t be around today, let alone keeping its head above water in the recession, were it not for telemarketing, and another company that finds carefully targeted telephone selling the key to relative prosperity in these hard times, is New York-based BMC Software Corp, which sells programs that improve the efficiency of IBM Corp mainframe operations: according to the Wall Street Journal, BMC, which did $31.4m net on sales of about $140m for the year to March, has 140 telephone sales personnel, each averaging 15 calls a day and it seems to be cost-effective, enabling the company to keep sales and marketing costs down to 30% of turnover, compared with an average of 40% to 50% for its software competitors.