Just going with some stats in the article.

These are just ballpark stats:

First spin worth 126%,
3 subsequent spins worth 140%.
10 players
13 gambling sites
Results fell in line with expectation
Total win was 900K.
Average edge was 36.5%
900K is 36.5% of a total wager of about 2.5 million
Each player ran about a 250K total wager
That would be 25K per site
Each site lost an average of 70K
Each player won an average of 7K per site.

I'm sure that players lost on certain sites. But with such a strong edge I'm also sure they made up for it in their winning sessions on other sites. It was probably something like booked a win on 10 or 11 sites and lost a little money on 2 or 3 sites.