I just entered my 4,000th Steamgifts giveaway. I've won 8 giveaways, with 3 of those being Group giveaways (from the CAG group) and 1 of them being a developer giveaway with 15,000 copies and 14,000-something entries.
So basically, I've won 1 out of every 1,000 public giveaways I've entered, or 0.1%.
Strangely, I've been entering giveaways there for 6 months, and 6 of my 8 wins were in the first two months.
Just thought I'd share.