I'm afraid I have to agree with the original poster and disagree with all the apologists.
I've been a gog.com customer almost from the beginning (Sept 2008) and I enjoy the service very much.
But ...
This is a business, not a free service set up by your pals, or a charity, so please think things through before making excuses on gog.com's behalf.
I constantly get messages trying to entice me to visit gog.com to buy more games (not a bad thing, mind you) or to alert me to the latest (and ever more frequent) promotion. That's fine.
But ...
As a responsible adult with many demands on my time and obligations to spouse, co-workers, family, children, pets, neighbors, members of the community, fellow trustees of boards I sit on, etc. (not to mention the constant clamoring for my attention from other businesses who want me to check out their latest offers), I can't devote hours solely to checking back with gog.com just because their servers are overloaded. This latest promotion with the daily free games, deals, pick from the 3 boxes each day and the countdown timer is clearly designed to entice me to check in to gog EVERY DAY FOR THE NEXT TWO WEEKS. That's what gog.com wants me to do.
So, it had better work and work well for the 5 or 10 minutes I'm able to grant each day. No excuses. I have plenty of other people that want to take my money and plenty of other things to do. I'm willing to give the benefit of the doubt and chalk this up to a mistake or growing pains, but gog.com needs to get it right or I'll start ignoring the promotional messages and eventually stop coming back. That's not a threat - it's just a cold fact.
Please, folks. Work out the issues with your infrastructure, because I really want to keep having a reason to keep coming back to the site.
P.S. As an added suggestion, the server infrastructure for existing customers needs to be separate from the sales-oriented infrastructure. Coincidentally, I recently reworked my storage infrastructure and alloted some time today to check and update my collection of already purchased games and was unable to do so due to intermittent server availability caused by a sale I didn't know was coming. That shouldn't happen.