I think a key point of arbitrage is that you do both of the transactions (the buying and the selling) at the same time.
This insulates the person doing the arbitrage from losing money because one or both of the markets changed (it is 'theoretically risk free').
So they would be theoretically be trading page impressions as they occur, to the highest bidder. Compare this to AdWords, which offers 'some amount of Cents' per impression.
You sell your adspace to opera, opera sells that AdSpace to someone else, dynamically based on market prices. (They could even sell it Google or whoever). Its like an ad stock market.
At least, that is my (very) speculative understanding.
edit: The key point is that they control the cache, so if you sell them ads and your page goes through the cache, they can insert it (whoever's ad it is) quickly. Otherwise it would be an extra level of indirection loading the ad.
This insulates the person doing the arbitrage from losing money because one or both of the markets changed (it is 'theoretically risk free').
So they would be theoretically be trading page impressions as they occur, to the highest bidder. Compare this to AdWords, which offers 'some amount of Cents' per impression.
You sell your adspace to opera, opera sells that AdSpace to someone else, dynamically based on market prices. (They could even sell it Google or whoever). Its like an ad stock market.
At least, that is my (very) speculative understanding.
edit: The key point is that they control the cache, so if you sell them ads and your page goes through the cache, they can insert it (whoever's ad it is) quickly. Otherwise it would be an extra level of indirection loading the ad.