How much can the league really be making there?

If they weren't making money on the games, they wouldn't be there but, really, why does the NFL play there?
Last year they played in Toronto. Not anymore. What gives?

A lot of it, from I hear, is about money.  If they expand the brand in other markets, and make them popular, it is just another revenue stream.

There has also been talk about the possibility of expansion teams in other countries.   However, most say that would be too costly with travel and everything.   Playing single games over there is a way of doing a soft market test.  

I am pretty sure most of the players don't like it.  They want to play fewer games and travel less.

I was in England for 4 years, and I can tell you that every year they played there, the game was sold out.  It was huge!  London was a massive football party scene and went mad on game day.  Plus when 1 pound = $1.60, I'm sure they made quite a bit of cash.

I'm surprised it is so popular overseas. I imagined it like me watching a cricket or rugby match, confused the whole time.

Rumor is they want to put a Nfl team in London  relatively soon (5 to 10 years)

Ha!  Cricket... I don't think anyone understands it.  The Btits loved the NFL games.  But they also really love almost everything American, so I can see where this might not be any different.  
What was really shocking was when I was at the Rugby World Cup in London and one of the main sponsors was Budweiser.  Seemed like a slap in the face to all of the Amazing beer over there to let Bud be so prevalent.  Both the Brits and the Itai's were sucking it down.  Must taste like water to them.

Sorry... back to the NFL.  I have also heard the rumor that London might very well be a tryout for a permanent team.  Jaguars maybe?

If London got an NFL franchise, I imagine the rest of the league would have to subsidize travel for every team to and from, obviously including the London team's travel.
Doesn't seem fair.