Online grocer Ocado has announced its aim to cater for the whole London area by Christmas. Launched earlier this year, Waitrose subsidiary Ocado operates from a warehouse in Hemel Hempstead, but is expanding to a 27,405 sq m premises in Hatfield next month. The company plans to invest £2m (US$3.1m) in an advertising campaign aimed at highlighting the company's availability within the London area, its free delivery and low product-substitution rate. The tagline "When did you stop being so demanding?" and comparisons between Ocado and its rivals will form the basis for the advertisements.