What kind of swag do you have? Booth babes?
The booth next to me had a girl decapitating a stuffed rabbit. The competition was uneven (and physical exhibitions are not a great fit for complex games anyway).
It was weird and not very sound financially to go there mostly for the Steam event. So I actively tried to make it hard to play the game (and steal my stuff!), as I hate people playing 15 minutes to tell me it's not their genre.
But there were still cool moments, like someone make his friend wait for 30 minutes to complete the mission, a couple playing together discussing most moves, and a 12 year old kid having a horrible start(more by the UI than the AI, sadly), but winning with a single character left at 3 HP.
Ok, this is beginning to sound like That which sleeps...
So overall, for a niche game dev, Gamescom/commercial area is a bad financial operation (and I suppose it is true for non niche dev, unless they already have a very popular game), as you pay a lot for very little (in term of actual WL). Most of the WL seem to come from Steam (the looped video stream had 250 average viewers in the first two days, while I had 10 visits. I know Steam's streaming numbers are very optimistic, but still, that's not even close).
But I got to talk with cool devs from Ishtar (The last Spell), Owlcat, Goblinz and Hooded Horse, so in a way, it is an overpriced meetup combined with an overpriced steam event. It was also exhausting.
But there are ways to make it more effective (going to the business only area, with some government backing, or getting into the curated events).