Because they are. And no, there is no client. You download a small, game-specific .exe which downloads the game's regular installer package.

Each GG game (or eventually as "game pack") has its own downloader. What you download is a file that is named after the game and that will download and install the game. GG does not deliver save forever ready to run /install game files like GOG , if you want to reinstall you will have to restart the downloader for the game even though that you may not have deleted (or moved) the downloaded install files..... (so GOG versions are far superior with respect to that!!!)
So reinstall requires an internet connection.
Also some games GamersGate sells like e.g. "A game of thrones: Genesis" is actually a Steam Game so you need Steam for that as it says on the game page :
http://www.gamersgate.com/DD-GOTG/a-game-of-thrones-genesis
(With respect to Steam games from GG then you might be able to "redeem" the serial or whatever in the Steam interface and let the Steam client do the installing and downloading)

I was gonna give away some games from GG's D&D pack but they aren't separate :(

Was that really a surprise?

I didn't even check out its info, just insta-got it :p Yeah it isn't really a surprise after checking the store page.

Yeah the GG thing downloads a hefty 10 gigs installer, and it is all the games in one go.

I guess I could save the installer, save it on a bunch of rars and back it up on a couple dvds for storage, but that is gonna be kind of a pain in the ass, haha. Same with Medieval 2 Total Warfare (which was ALSO a pain in the ass to install, but manageable, eh). Still, less than 6 bucks for all the infinity engine games AND ToEE? Damn good deal. Even if that means I have now repeats on physical media AND GOG.

It's better to put it on a backup drive.. I bought WD 1.5TB external HDD for $70 during Christmas time on Amazon... such a good deal and now I can backup whatever I want.

Yeah. Having backup drives is always a good idea.
Also, neat, the D&D collection installer already comes in a bunch of .rars, which is always neat. Will just copy those to another folder before finishing the installation, still less convenient than the GOG packaging (all in one bunch, damn) but still better than having one giant-ass installer.

Can't see the daily yet but on my wishlist The Guild 2 Renaissance is -75% on Steam so I guess that might be it. Does seem likely since it's also on sale elsewhere I believe.

*poof* and there it is, The Guild 2 -75%

Correct me if I'm wrong, but I believe the latest expansion (which happens to be Renaissance) contains everything that came before it, right?

You trying to tell me that the most awesome game on existence is on sale on Steam?

It's like they don't want us to use our coupons on specials. Blargh. :P

Actually Nordic Games coupons stack with this one, best coupon cuts it down another 50% :)

Actually there are at least 3 Guild games on sale on Steam :
http://store.steampowered.com/search/?snr=1_4_4__12&term=The+Guild

P.S.
Save even more . buy it as a collection :
http://store.steampowered.com/sub/4829/

I don't have any Guild 2 game and I do have the Nordic 50% off. What should I buy if I just want the best version? The collection for €5 (€2.50 after discount) or just one of the games? I'm honestly confused what is an expansion and what is not.