[quote name='Detruire']If they're going to do so, it'd be courtious to at least mention that sort of thing in the same post. Then someone who comes along after the discount has ended can see that it wasn't all that special, after all.[/QUOTE]
Well, the motivation was just that I was happy with all the deals GMG was offering. Then someone asked me, so I explained. Since I guess some people might have missed this trade-in credit system, let me further explain.
1. Every now and then GMG offers free games. You can hear about these free games sometimes on CAG and always on slickdeals. You should always get these games, even though they are usually crap, because...
2. You can trade-in the crap games for credit. The credit is worth anywhere from $5-$0.50. Usually it's just $0.50 but you never know.
3. You then save up the credit. After a year, cash it in for a free game during the big sales (BF and Winter).
The Battlefield deal was more tricky. You had to sign up for promotional emails from Origin and receive a one-person code. The only reason I knew was that people were bragging about a previous deal from Origin limited to the promotional emails. So, hoping to get in on a future deal, I signed up for promotional emails from Origin even though normally I don't sign up for spam.
So, by hearing about other people's deals, I learned what I might want to do to score some free stuff in the future even though I could not get in on the deal immediately.
Instead of calling it rubbish, I suggest you consider it potentially useful information. This attitude worked out well for me in the past.
And by the way, I frequently will start threads on either slickdeals or CAG about deals I hear from those or other sites, helping the community save money even though it takes time and provides me $0 compensation.