I'm pretty sure Krebs is in the game for the publicity, not the reward money. The publicity and "staying relevant" as a security researcher has a lot more value than a nebulous reward that likely will never pay out.
Based on the typical wording when reward money is offered, I strongly suspect almost no reward money is ever paid out. It typically requires arrest and prosecution (often conviction) and there are plenty of opportunities for the lawyers to say "sorry, your tip did not qualify" even if someone is arrested and prosecuted.
I did not find a direct offer, but Wired has a quote[1] (most sources don't even provide a quote!):
“Today I can confirm that Avid Life Media is offering a $500,000 reward to anyone providing information that leads to the identification, arrest and prosecution of the person or persons responsible for the leak of the Ashley Madison database,” Evans said, according to the BBC.
Update: Odd. The BBC link in the Wired story has quotes from "Bryce Evans of the Toronto police", but does not have the offer of a reward quote that Wired quotes.
http://www.bbc.com/news/technology-34044506
Based on the typical wording when reward money is offered, I strongly suspect almost no reward money is ever paid out. It typically requires arrest and prosecution (often conviction) and there are plenty of opportunities for the lawyers to say "sorry, your tip did not qualify" even if someone is arrested and prosecuted.
I did not find a direct offer, but Wired has a quote[1] (most sources don't even provide a quote!):
“Today I can confirm that Avid Life Media is offering a $500,000 reward to anyone providing information that leads to the identification, arrest and prosecution of the person or persons responsible for the leak of the Ashley Madison database,” Evans said, according to the BBC.
[1] http://www.wired.com/2015/08/ashley-madison-offering-500k-re...
Update: Odd. The BBC link in the Wired story has quotes from "Bryce Evans of the Toronto police", but does not have the offer of a reward quote that Wired quotes. http://www.bbc.com/news/technology-34044506