Few outside of Apple have seen an iPad in person, but that hasn’t stopped a rush of preorders for the touch-screen tablet device.

Sources have told The Wall Street Journal that Apple has sold 300,000 iPads since Mar.12 – iPad launch day – alone. Apple could end up selling more iPads in the first three months than original iPhones sold the first three months after its debut, according to those sources.

Launch day sales numbers are a big indicator of just how successful the product launch proved to be. That’s part of the reason analysts like Gene Munster clamor to be the first to guesstimate initial sales figures. Munster estimated that up to 700,000 iPads had been sold on the iPad launch day. That turned out to be wrong. Apple says that 300,000 iPads were sold through their online pre-orders, Apple stores, and partner sales.

Apple is coming down to the wire on striking content deals for the iPad. Negotiations are ongoing between Apple and media companies for discounted TV shows via iTunes, according to sources. Partnerships between Apple and newspapers, magazines, and textbook publishers are also still yet to be cemented, and have “been put on the backburner” in favor of other types of content.

Besides content, some accessories for the touch-screen device are also a little behind schedule. Both the keyboard dock/charging station and the 10W USB power adapter won’t be available until May.