Rush or no rush?

[schroedy]

At limits from $10/$20 to $20/$40, mainly shorthanded games, I am up a LOT in the last two weeks (somewhere around 2.5-4.0 big bets/hour (I don't keep THAT detailed of records, just a monthly total of earnings)).

Coincidentally, about a month ago I made a resolution to myself which I have kept, NEVER to put any money in the pot unless I was the favorite, or unless pot odds justified a call. Specifically, I have tried to focus on always being ahead before the flop (obviously not always possible, but a laudable goal), and then just make sure I don't lose too much, if any ground, later on (rather than trying to wring total value out of every holding after the flop).

So my question is: with faster deals on the internet, and more deals in the first place because of shorthandedness, are these sustainable earn rates or am I basking in the glow of an extended lucky streak?

(I have made some incredible hands in the streak -- quads three times, a Royal Flush, etc. but I have logged some hours as well. I have also had my share of disappointing rivers, or been unlucky enough to catck KK against AA and the usual sort of things that cost a lot of chips for an aggressive player.)