Starting today, Tampa Bay residents will be able to order Costco groceries straight to their door through Shipt, an online grocery delivery service. Shipt's new partnership with Costco will deliver from four Costco locations in the Clearwater, Tampa, Brandon and Wesley Chapel areas.

The delivery service covers any grocery item from Costco, but does not include apparel, furniture or electronics. A Costco membership — which is typically mandatory for shopping at its wholesale-priced warehouses — is not required to purchase the products through Shipt.

To lure customers, Shipt is offering a two-week free trial to Tampa Bay residents, including $15 toward their first order.

As an online grocery marketplace, Shipt partners with a variety of retailers. Subscribers can order groceries from one of its partners through a mobile app and choose a one-hour delivery window for the groceries to be delivered. Subscriptions to the service cost $99 per year, which gives subscribers unlimited free deliveries.

Shipt is one of a few grocery delivery services in the Tampa Bay area. It competes with companies such as Instacart and WeDeliverGroceries.com. They're all powered by what's known as the gig economy, centered on part-time, freelance and temporary jobs, or gigs.

Independent contractors hired by Shipt, known as personal shoppers, will pick out and deliver the groceries. The service struggled initially to hire enough personal shoppers to meet demand after it launched in 2015, particularly in St. Petersburg.

Contact Malena Carollo at mcarollo@tampabay.com. Follow @malenacarollo.