Yieldify’s software tracks mouse movements to predict when a website visitor will leave — it can then tempt him or her to stay with a promotional pop-up based on the person’s viewing history. Users who abandon their purchases may also be tempted back by a series of emails. More than 1,000 websites around the world use Yieldify’s technology, and its customers include Virgin Trains and Domino’s. Co-founders Jay Radia, 32, and his brother Meelan, 28, have raised $19.5m (£15m) from investors including Google Ventures, Softbank and Hoxton Ventures. They pushed annual turnover to £9.1m in April.