donsanderson: Be interesting to know whether GOG makes more from sales/promos or full price purchases.
If I'm not mistaken they've mentioned before that the big promos bring in the biggest revenue. It's not really a surprise though because there is almost zero per-unit cost to the games as they're just bits on a hard disk rather than in a warehouse consuming space that costs money, so the per game overhead is negligible. It comes down to cashflow in the end, and while some people will buy any game they want at it's regular price, they're going to be finicky about what specific games they'll pay full price for too, but when games are on sale people are more likely to buy them across the board and that means buying games they'd never pay full price for. Then there are people who generally wont pay full price for games at all, waiting for sales to do their bidding, or whom only will pay non-sale prices for those rare gems they just gotta have.
So promos like this bring out a lot of purchases that would just never happen at all and generate no cashflow as a result but end up generating cashflow due to the sale. If they end up selling 500 copies of a game at $2.49 in a promo versus selling 5 copies of it at $9.99 in the same timeframe not on promo, or even 50 copies of it non--promo, the promo pricing brings in more cashflow across the board. Plus, promos are intended not only to bring in more cashflow from existing customers and whimsical buys that would otherwise never happen, but to also draw in new customers to the site that wouldn't have purchased anything at all before, and then hopefully get the indoctrinated into the fold as repeat customers as well. :)
In short... they make a killing. :)