Millennial Media’s March report on trends related to its mobile advertising network provides a few more clues about the impact of the iPhone 4 on the Verizon Wireless network – and tablets in general.

The iPhone grew 17 percent month-over-month and iOS grew 11 percent month-over-month, Millennial reports. That was largely tied to the growth of the Verizon iPhone, which accounted for 8.2 percent of iPhone impressions in March, the first full month in which the device was available for sale.

Broken down by app revenue by platform, iOS apps represented a 47 percent share, while Android apps represented a 36 percent share. However, Android remained the leading smartphone OS for the fourth consecutive month, with a 48 percent impression share. Fourteen of the top 20 devices on Millennial’s network run the Android OS.

Connected devices, which include the iPad, iPod touch and Samsung Galaxy Tab, increased 21 percent month-over-month and now make up 17 percent of the device impression share, compared with 64 percent for smartphones and 19 percent for feature phones.

The BlackBerry Curve reclaimed the No. 2 position in the Top 20 mobile phones, and the BlackBerry Torch grew 23 percent month-over-month. The OS from Research In Motion experienced a 29 percent growth month-over-month.

The firm reports that the increased usage of connected devices over its network contributed to a 17 percent increase of Wi-Fi month-over-month.