I believed in most cases, almost the majority of gambling streamers do have a raffle of sorts or giveaways.

Having that giveaways or raffles is the most effective way to lure and attract viewers to the stream. These viewers don't need to really watch the stream but they will just follow the instruction in order to be eligible for the raffle like staying on that stream the entire session etc.

In the huge competition of gambling streaming and the difficulty to attract viewers, without a giveaway, it's hard to cope especially for the new streamers.