Sure they can afford it. How much does it cost to burn a setup CD $.50, $1.00 maybe? Then maybe a couple bucks for the box. Say they give away 1000 copies, and it cost them $10.00 (I am sure closer to maybe $5). That is $10,000 dollars. Now only 1% (10) of those initial 1000 user would need to purchase additional licenses, or re-new the next year for them to make there money back (assuming the pro version). What better advertising could you possibly buy then that?
Hell that doesn;t even account for tax benefits they may get from giving away their product.