This is not a bad idea, but it would be much better if you offered bigger Bitcoin rewards, that way you would attract more attention and give more incentive and motivation to hackers.
Yep I agree, that is why I included QR codes for both bounties, anyone who wants can send to those addresses and increase the bounty.
Presently (and ironically be design), if you win the initial bounties you could use it to pay for a 1 year subscription to each service :-)