If GOG do this, I'll back up anyone who say that GOG are 'slack as a business.'

A good manifesto if I ever heard one (the whole thing).

It's not quite fair to compare a gog sale of an old game to a Steam sale of a modern game. Steam may be able to put modern games at crazy low prices once and awhile, but that's because it is a different business. They also sell new games at $50. The small amount of profit from a sale can be compensated for with the money gained from new release sales.
For GOG, everything here is cheap. You can't expect a sale to be as dramatic here when their always offering great prices. I'm surprised they did such a huge sale this holiday and it was far from stale. I bought a ton of games and was happy with my purchases.

Ok, so $9.99 is to those above as Steam's sale prices are to $6.99. Changes nothing, GOG's sales/prices are still uncompetitive.

Oh, I am sorry, I used the term to as a metaphor, to represent the homogenous group with identical and illogical positions. I should have explained myself better.

Only if you consider the short term... never want to give a purchased game to a family member or friend.... only if you consider the bonuses, the lack of DRM and the level of service not to be something worth paying for....
I do have a large collection of games on Steam but if there is a game on Steam and the same on here I'll buy it here even if it is a few dollars extra - I can't believe there are quibbles over a few dollars at most.... no sense some people (pun intended ;) )

bah, practical reality is the only meaningful frame to any sale. And the practical reality is that GOG's sales and competitiveness in general are very lacking compared to their competition.

What competition?
What other services sell an abundance of older titles, and focus solely on this niche?
None.
There is some crossover with titles on multiple platforms, and often having slightly varying price levels, which is to be excpected. Using these few titles as the sole examples that GoGs business model falters in light of the competition is complete fallacy.
In addtion, the "practical reality" is that comparing Steam with GoG is not a logical move. Steam is old, huge, and mainstream. GoG is new, small, and niche. It is not GoGs purpose or goal to be able to compete directly with Steam. So why debate?

Bah. Games are games are games are games are games. If Steam has a sale on, and so does GOG, and you are planning on spending $20 on games this week, it puts GOG into direct competition with Steam, so don't give me that rubbish.
It is objectively true that Steam and D2D have better sales than GOG. In case some people here don't know what objectivity is, (which I suspect is true for the vast majority), it means indisputable fact. I could copy/paste the stats for you to prove it, but you already know it to be true.
85% off beats 30% off, case closed.

Oh, I'm sorry, I thought you were referring to cute, woolly animals. Then again - this use of the term is not derogatory, uncalled for and unjustified, so I might be wrong...
You might as well say "no sane person uses GOG".
While the community "features" of GOG may be underdeveloped at this point, the community in itself more than makes up for it. Then again - I can't compare it to Steam's equivalent, as I simply don't lurk their boards that much...
All in all - we don't need and don't WANT a GOG client.
There's more to "practical reality" than you think. If you choose to perceive only a single aspect of it, your view of reality is narrowed down too much.
Also - as I've said before - if you are going to say it boils down to "Steam - cheap, GOG - not as cheap", then there's no point in further discussion, is there ?
We KNOW Steam can be cheaper than GOG - they simply have the power and influence to do so. SO WHAT ? If you are here ONLY because you want to buy cheap games, then you're missing the entire point of GOG.
Now read my GOG manifesto one more time, say to yourself that you don't care about all that stuff and enjoy your day knowing that "Steam is better, simply because you like it more".
Also - yeah - categorical fallacy (usually called "apples to oranges"). GOG doesn't want to be like Steam. That's why a lot of us think GOG is great - we don't have to deal with all the Steam-related issues. If you think "the way of Steam" is better - knock yourself out.
We're not comparing games here. Not really. Sorry.
That puts a tuna sandwich in direct competition with a condom.
Want me to spell it out ? You can buy both or you can buy one and not the other. How the fudge does that make them related ?
Compare to the lost of people here who benefited from both sales.
I'm tempted to make a list of things you think about the GOG community. So far you think that we are irrational, make identical (!) choices and don't understand words like "objective"... My, if I weren't a braindead zombie, I'd venture a guess that you don't like us ;).
50% more FPS doesn't mean a lot when you start out at 4... Don't let math fool you.
As people have pointed out - the highest price @ GOG is $9.99. At 80% off - that would be $1,50. Not happening.
BTW - what's that free game that Steam gave out on holidays called ? I must've forgotten the name...
Also - see the above on why GOG is not about being cheaper than Steam.

If we're doing this, shouldn't we talk about the absolute dollar values, then (if you want to get the most of your weekly $20 budget)? an $8 game beats a $10 game, even if the former is a $10 game getting 20% off and the latter is a $20 game getting 50% off.

No, we are talking about savings. Of course, you are so biased, that the PLENTITUDE of $1-$2 dollar games on Steam, and $5 games on D2D's past sale sailed right under your radar, because you intentionally shut it off.
That's ok, you are entitled to your biases, just like everyone else is.
One thing though, you ARE NOT entitled to ACT as if those biases are part of your objectivity. Facts are facts, opiniosn are irrelevant, and 85% is better than 30%, FACT.

No dice.
You should have learned by now that I don't fall for that kind of thing. Even if I *did* want to, that wall of text would deter me even if there *was* cake at the end.

Yes you could say that if you want to break down the point (even though the $10 game is likely to be a old budget crap title and the $50 title is likely to be a new superior regulerly played (multiplayer) title) but then your also not considering new games at the $10, 20, 30 mark. Steam had these for $1 (shooter games, ghost master(is on here)) $2(sniper elite, defense grid), $5(tourchlight), $8(gta 4 insane game).
Vestin it makes them related because they are 2 businesses selling games with different market strategies. One is differentiation niche the other is cost leadership. Just because they attract different customer types does not mean they cannot compare as they can. People are going to compare the aspects of steam and gog, especially the games and prices and see that steam has alot of the old games on gog for cheaper and other old games like the lucasarts games and go their. This is because customer assume GOG is just another business they have not built brand loyalty.
Which brings to the point I was trying to make earlier GOG needs one price point to compete every game on here I feel is not worth $10 but $5.99 is an alright price. This will draw new customers in as its no longer more expensive than steam and then once they experence the brand may purchase of GOG even if it is more expensive.

Take a look at this. Pretend for a moment that GOG is set A and Steam is set B. The union of those sets does indeed contain some games, but even disregarding that both sets are composed of games. If there was a tuna flavored condom involved in your argument you might have made some sense.
Anyways, all I really wanted to say is that Steam and GOG are obviously competitors, and only an oblivious consumer would claim that they aren't. Sure, GOG is a little more magical than most sites, but it's still a business that needs to be treated as such to enjoy any measure of success, and ignoring that is foolish.

But pretending that the percentage saved in a sale is the only thing that can sway customers is just as foolish.