Costco to offer home grocery delivery in 50 cities by the end of 2017

(Photo by Justin Sullivan/Getty Images)

(Photo by Justin Sullivan/Getty Images)

Costco customers across the country will soon be able to get groceries delivered to their doors, according to the company that will make the deliveries.

Shipt, a subscription delivery service, said in a news release Tuesday that it has begun delivering orders for Costco customers in the Tampa area.

According to Costco, the company plans to extend the service to 50 U.S. markets, serving more than 30 million households, by the end of 2017.

According to a story from Fortune, the move comes as grocery retailers work to figure out the growing home delivery market in an industry with stiff competition.

Online grocery sales hit $7 billion in 2015. That number is expected to more than double by 2020, according to Statista.

Shipt will charge members $99 a year for unlimited grocery delivery, and will offer free delivery for two weeks for Tampa-area customers, according to the news release. Customers will also get $15 off their first Costco order. Shoppers can download and place orders using the Shipt app.

Costco has already teamed up with the company Instacart, which delivers groceries from the retailer to customers in 19 states and the District of Columbia.