You could spice up the sales a bit if you'd introduce a reward system.
Let's say, for every purchase you give 5% back to the customer as virtual currency (GoG credits maybe?). So for a 9.99 USD deal the reward would be 0.5 credit.
1 credit would be equal to 1 USD and then the customer can buy games for this virtual currency given that he/she has enough of this credit.

ezt most komolyan gondoltad?

Isn't the extra content reward enough?

And the lack of DRM.
And the awesome support.
And the community.
And the cheap price tag.
And the wide selection.
And the virtual shelf.

Speaking for myself, a small payback wouldn't really convince me to spend more money here - the quality of GOG's products and services guarantee that I only shop elsewhere if GOG doesn't have what I'm looking for (and even then, I'm more likely to wait for it unless it's a new release). There are also quite a few titles that I have bought or would buy on GOG that I wouldn't buy on a DRM-restricted service, even at a lower price. In other words, I'm already as loyal to GOG as I am likely to get.
Frankly I would be surprised if GOG is not operating at a net loss, given the small commission they take and the amount of labor that goes into finding, negotiating, fixing, updating, and releasing these titles.

Nope, bad idea. GOG already gives us games at a great price on a regular basis, then pads it with weekend sales, the occasional giveaway, plus continuing support and adding additional extras. GOG would end up losing money if they implemented a "rewards system" like that. They can drum up more business with what they already have been doing anyway.

Probably a bad idea ... the current awesome product with weekend sales is great. Not sure they really need a reward system. Their sales seem to be doing fine without it.
Might be interesting if only used on non-sale items.

Okay, this just got me thinking, what if they did implement a points system, but with those points you could only get things like T-shirts, stickers, mugs, "Shelf 2.0" enhancements from last year's April Fool's joke, etc.? That, to me, seems like it might be a good thing for GOG's advertising while not necessarily impacting their bottom line that much (especially the "Shelf 2.0" stuff).

GOG's parents, CD Projekt already do that with their eXtra Klasyka games, they call it vPLN [virtual polish zloty], which is virtual currency that can lower the price on more expensive titles.
If GOG started to make it's own games in the retro style [which is a wet dream job of mine], virtual money on GOG's merchandise that would lower the cost [to some extent] on those more expensive self made retro games would be a great idea. ;)
Let's say, You buy a $9'99 game, and get a, i dunnae, a $5 discount on their $30 buck game. Sure, why the hell not!
But since GOG is not into creating their own titles [or those based on licenses], such an idea is not really all that cool. It's like saving up on big games, by walking to the store, instead of driving/using a bus. ;>

At first, I thought that's what Gyokzoli wanted.

Well, if he did, that's not what he said. He specifically mentioned building up points to spend on games, not schwag.

Gamersgate do something similar with blue coins, which are also rewarded for reviews. I can't say I've found it to offer any greater enticement, personally.

I know.

It would be nice to at least have the option for those non-shiny boxes, even if the rest is outside the realms of possibility.