Apple's marketing strategies are clearly second to none and once again, despite all the sour faces surrounding the iPad, the company is grinning like a cheshire cat with some 300,000+ iPads sold on the U.S. launch day (April 3).

However, that number does include all the deliveries of pre-ordered units to customers as well as deliveries to channel partners such as Best Buy and Apple Retail Store sales; so there might be still a significant number of them nestled on store shelves. Nonetheless, it's a big BIG number in a single day.

Reflecting back on Apple's previous big release with the iPhone, only 270,000 of these were solid during the first 30 hours of being on the market, but saw sales in excess of a million of the iPhone 3GS units during that handset's opening weekend.

Some other interesting stats of note about the initial selling days of the iPad; some 1 million plus app downloads and over 250,000 ebooks from the iBookstore took place during launch day; Steve Jobs quick to take note of this and saying "iPad users, on average, downloaded more than three apps and close to one book within hours of unpacking their new iPad."