Every GA U create increases your contributor level. U can check your progress under "My Stats" which can be found next to your avatar on the right top corner.
Keep in mind that Games that were previously free will not contribute any points for leveling up, also games that have been bundled previously will give U less points than games that have never been bundled.
A popular site to buy bundles from for example is HumbleBundle.com, which U may or may not know of already.

I should note that if U win a Game here on SG it is expected that U redeem the game for your own library in Steam and not make another GA with the same key of the Game that U have just won. Many people frown upon this practice.

From the FAQ
If I win a game, can I regift, trade, or sell it?
According to our guidelines, no, all games you win must be activated and redeemed on the Steam account you used during registration. Failure to activate games you have received will result in a suspension.