A source familiar with Google's plans told Mashable that Google Shopping Express is about to roll out to the entire Bay Area, filling in many of the suburban areas outside San Francisco that Google initially left out at launch. Google will start accepting sign-ups for beta testers in the additional neighborhoods later this week or early next week.

While Google doesn't have any firm plans to expand to other cities, the source tells us that the delivery service has "been doing well enough and worked out the kinks to expand a little more." The number of orders per day is steadily increasing, according to the source, and the team working on the service has grown as well.

Since launching Google Shopping Express, the team has focused on expanding the number of products offered from each of its nine retail partners, adding several new features like high resolution, 360-degree images for browsing and scaling operations and delivery. As Mashablepreviously reported, Google does not operate its own fleet of couriers, but instead works with partners who wear branded Google Shopping Express uniforms and drive branded Google delivery trucks, as seen above.

Even as it continues to improve and expand on the service, Google faces tough competition from more established businesses and startups in the space — not to mention the fact that Google has a mixed track record when it comes to commerce. Google recently announced plans to shutter Checkout, its payment processing service, and the company has struggled to gain broader adoption for Google Wallet.

Google declined to comment for this article.