To ensure the Windows Mobile Marketplace is populated with a higher percentage of quality apps, the site will restrict the number of apps a developer can submit each day to 20.



From InformationWeek:

Some developers have been bulk publishing, according to Microsoft, which means they each are submitting hundreds of apps in just a few days. The apps meet all of the publishing requirements so anyone that has downloaded one, or several, of the apps don't have anything to worry about. Instead, the problem is it lessens the consumer experience when browsing through the store by pushing out other apps from the "New" category and filling it up with content from just a few publishers.

  Microsoft Cracks Down On Bulk App Publishers