Only one in five companies with an online presence get the performance they expect from their websites.That's the damning finding of research conducted by automated testing company Mercury Interactive over the last 10 months. Furthermore, Mercury found that 70 per cent of the sites cannot cope with the traffic they're receiving, failing to reach 30 per cent of their planned traffic throughput. Around half achieve just 15 per cent. Asaf Landau, e-services product manager at Mercury Interactive, said: "There is no single reason for these failures. In one company in France, we found the load balance for four servers was balancing on IP addresses - this left three of four web servers processing fully and one simply static. "But, you find a problem like that and sort it out, and then find the next problem or conflict. If you find web and application servers and the database are all only working at 50 per cent - then you know that you have a pipeline problem. In general, performance increases by at least 20 per cent with each test." He added: "Servers are infinitely configurable, but sometimes there are more straightforward problems. "With one European post office's ecommerce site, we found as the number of virtual users hit 20 per cent it became stagnant. When we looked closely we could see its ISP was only giving them 420Kb of bandwidth, instead of the 2Mb it had contracted for in the service level agreement." Graham Titterington, senior analyst at Ovum and a testing specialist himself, said: "Testing is a necessary part of the development process, but tends to be skipped. But now customers are suffering, there is the commercial incentive to test and get it right. There's no doubt people who get poor response - poor service if you like, don't come back." Mercury's Active Test is based on scripts of the various business processes the website is to handle such as browsing, buying, contacting and registering. Through a set of global 'points of presence', these scripts access the site, and attempt to carry out the processes on the live site while Mercury checks response time and capacity.