That's what Google returned but I didn't think it made sense in the context. I guess he means to say you can trade one for the other? That doesn't make sense to me to be honest. I did like the article though.
I think the author is using "arbitrage" a bit loosely/metaphorically, as "a new opportunity that seems low-risk that has only just appeared, and, being such a great opportunity, will thus likely only exist briefly till the first few actors exploit it till it's not really an available opportunity anymore"
The looseness comes from the fact that traditionally an arbitrage opportunity really is theoretically nearly zero-risk while I think the author is using it here in cases where it's a bit more complex. But the analogy at least works in highlighting the aspect of these opportunities being temporary in their existence, like the joke about an economics professor and student seeing a twenty dollar bill on the ground and the professor ignoring it, quipping "If that was a real twenty dollar bill, someone else would already have picked it up off the ground"
Arbitrage may be the most incorrectly used word in Silicon Valley. People usually mean they buy something here and sell it for more there - but that's not arbitrage.