Here's an idea:

If you enter this giveaway, please create a giveaway of your own.

On that giveaway, please include a similar note, asking entrants to create a giveaway... and on that giveaway, include a similar note asking entrants to create a giveaway... and so on...

Also, consider supporting the Community Train 3.0. a simple Bump is good enough.

Let's make September "Giveaway month" on Steamgifts!