Ocado is to embark on an “aggressive” marketing plan over the next two years to increase shopper numbers.

The etailer has been reticent to spend on marketing before now as capacity contraints have held back the chase for customers.

But its Hatfield facility will eventually handle 160,000 orders a week and its new Dorden distribution centre in the Midlands, set to open early next year, will add a further 120,000 orders a week creating the need to boost customer numbers.

Ocado chief executive Tim Steiner said: “We have never been the Hard Rock Cafe with a queue out of the door, we have been constrained by our own capacity. We have been attempting to aquire customers who will shop off peak and will continue to do so.

“We have never had headroom of more than 2-3% in terms of order growth potential. We now see we can do something more aggressive with our proposition.”

Ocado has already begun to target shoppers who seek to deliver outside of peak hours with a Groupon deal revived this week. It offers £40 to spend at Ocado.com and a 12 month midweek delivery pass valid on Tuesdays to Thursdays when customers spend £39, down from £69.99.

Yesterday Ocado’s full-year pre-tax losses slimmed to £2.4m from £12.1m in 2010 while sales grew.

Sainsbury’s also shifted its delivery strategy to reward off-peak customers this week. The UK’s number three grocer has put up prices on peak time delivery slots while bringing down the price of its cheapest Tuesday to Thursdays slots from £3.50 to £2.75 and increased its top end from £6.50 to £6.75.

A spokeswoman said: “We’ve introduced a new lower price of £2.75 for certain off-peak slots, and deliveries are still completely free of charge on Tuesdays, Wednesdays and Thursdays for orders over £100. 

“We’ve increased the spread of charges from £2.75-£6.75 and we continue to offer our popular one hour delivery slots which customers tell us is really time-saving and convenient for them. Despite increasing costs we haven’t put up our online grocery delivery charges for more than three years.”