During the one-hour long earnings call this afternoon, Research In Motion spent a good portion of it justifying its spending spree to analysts who questioned gross margins and expenses during the second-half of the year. Analysts weren’t the only ones who worried. In after-hours trading, the stock was trading 20 percent lower, representing a drop of about $20 to just below $80 a share. Earnings Call.

To be sure, RIM (NSDQ: RIMM) has a lot of things to be encouraged about. During the quarter, it said it owned about 50 percent of the smartphone marketshare in the U.S., that about 60 percent of its new subscribers were consumers, not its bread-and-butter enterprise users; and about half of the people buying its latest 3G phone, the Blackberry Bold, are consumers. And in the current quarter, it expects to launch the Pearl Flip, launch the Blackberry Bold in the U.S. via AT&T (NYSE: T), also an unnamed phone on “a new platform.”

Still, it was the expenses analysts were concerned with. In Q2, expenses, including research and development, selling, marketing and administration and amortization increased to $605 million, up from $491 million in Q1, and up from $311 million in the year ago period.

Here’s some of Balsillie’s justifications for the spending, hinting at new product launches and revenue streams:

—Growth period: “We believe we are entering the time of tremendous opportunities for the remainder for the fiscal year. It puts RIM in a tremendous opportunity to gain share in the smartphone market…“We are in a surge type situation. You are going to see a rapid set of product introductions. To us, that’s unambiguous. We think we have new revenue streams coming, and investors need to decide if they want that off of a small or big customer base. It’s all about adoption right now because that’s going to be the basis for phenomenal leverage for a long time…There’s new revenue streams, and cost reductions, and with a super-charged top line, if we give up ground for short-term gratifications, that’s not in the interest of our investors, not even close.”

—Leadership position and new revenue streams: Balsillie said he just returned from India, where he sees so much growth potential. “I think we should invest more. It justifies tremendous attention.” He said if you get the right product, the right price and build an ecosystem, RIM can leverage its leadership position it has worldwide…As for new products and services “it’s coming mid-ish and late in the quarter, we’ll get a even bigger bump from them next quarter, and our new revenue streams—which I have to be careful about—will become more apparent as long as the company holds leadership position as it goes to mass adoption. You have a lot of indicators at CTIA that these things are moving a lot faster than I even anticipated. That means whatever value of our position has to the world it represents more.”