Here are the latest update from the Windows Phone 7 Developer Worlds that went live this month.

Here are some of the latest numbers: Windows Phone Marketplace currently offers more than 9,000 quality apps and games and enjoys a base of over 32,000 registered developers, delivering an average of 100 new apps every day. There have been over 1 million downloads of the developers tools for Windows Phone 7.

Trial version help you sell more

Trials result in higher sales by the numbers:

• Users like trials  - paid apps with trial functionality are downloaded 70 times more than paid apps that don’t
• Nearly 1 out of 10 trial apps downloaded convert to a purchase and generate 10 times more revenue on average than paid apps that don’t include trial functionality.
• Trial downloads convert to paid downloads quickly. More than half of trial downloads that convert to a sale do so within the 1^st 24 hours of trial download, and mostly within 2 hours of trial download.

Microsoft Ad Control is gaining traction

By the numbers - ad supported Windows Phone 7 apps are:

• Roughly ¼ of all registered U.S. WP7 developers have downloaded the free Ad SDK for Silverlight and XNA
• Of ad funded apps, over 95 percent use the free Microsoft Advertising Ad Control
• Monthly impressions from our Ad Exchange has continued to grow by double digits – impressions increased by 376 percent since January

Ad Control, the first wave of “How Do I” videos are now available on MSDN:

1. Create an Ad in a Windows Phone 7 XNA Game App
2. Register Ad-Enabled Windows Phone 7 Apps
3. Measure Ad Performance of Windows Phone 7 Apps

Boarder International App submission for Free Apps through Yalla Apps

As of today you can start submitting your free applications in developer markets that are currently not covered by Microsoft.

To submit your Free application if you DO NOT belong to one of the Marketplace supported countries, go to: Yalla Apps

Marketplace Policy Updates: Free App Marketplace Submission upped to 100 and other news

Microsoft has been revisiting a few of our Marketplace policies based on feedback from developers to reduce friction and cost, word for word:

1. We have raised the limit on the number of certifications that can be performed for FREE apps at no cost to the registered developer from five to 100. This was a common request from developers which we are glad to implement after building alternate methods to ensure that users can find and download high quality apps.

2. We have converted policy 5.6 - related to the inclusion of contact information for support - from a mandatory to an optional policy. This is still a strongly recommended best practice, but we recognized and responded to developer feedback that this policy was creating excessive drag on the certification process for developers without commensurate user benefit for all apps.

3. We also understand the desire for clarification with regard to our policy on applications distributed under open source licenses.  The Marketplace Application Provider Agreement (APA) already permits applications under the BSD, MIT, Apache Software License 2.0 and Microsoft Public License.  We plan to update the APA shortly to clarify that we also permit applications under the Eclipse Public License, the Mozilla Public License and other, similar licenses and we continue to explore the possibility of accommodating additional OSS licenses.

Enjoy and happy coding!

Official Blog Post for reference.