Lance Whitney/CNET

Microsoft is now restricting the number of Windows Phone apps that it will approve from a single developer to 20 per day.

In a blog posted yesterday, Microsoft said the new restriction is aimed at cutting down on "bulk app publishing," a process through which developers can flood the Windows Phone Marketplace with hundreds of apps over the course of just a few days.

Though these apps may meet Microsoft's certification guidelines, the company is concerned that such apps can push other recently-published apps out of the "What's New" category, thereby degrading and "reducing the diversity of the shopping experience" for Windows Phone customers.

Microsoft is basing the 20-app limit on its own evaluation and feedback from users as well as developers. Developers can still submit more than 20 a day, but only 20 will be certified per day.

To further deal with bulk app developers, Microsoft said it's already removed certain apps from the Marketplace, giving those developers an opportunity to refine their apps in an attempt to cut down on the sheer quantity of them. The company has also offered to work with developers to help them better create fewer individual apps instead of producing large numbers with similar functionality.

The new policy goes into effect immediately, though Microsoft added that it's open to changing the limit based on the growth of the Marketplace and further feedback from customers and developers.