I'm one of those travel hackers. It's a special name for an ordinary hobby: I'm one of those people always looking for the best credit card out there to benefit from their bonus.
For instance, this summer, before I went to central america, I've ordered two new credit cards. One that gave me a 150$ bonus for free and another one that gave me a bonus of about 270$ for a fee of 39$ (plus some super great advantages).
Via www.ratehub.ca, you can compare all the credit cards in Canada. It's great because some of them have very interesting sign up bonuses. Before a big expense (like some plane tickets for instance), I order a new card that requires an expense of 1000 or 1500$ in the first three months to get a reward of 150, 200 or 300$. In other words, my expense is 20 or 30% lower because of the sign up bonus.
And some of them have super advantages, like free access to VIP lounges in airport (where you can eat endlessly or drink like a rock star for free), insurances about a delayed flight (500 or 1000$ if your flight has a delay of 4 hours or more), zero exchange rate when used in another country, and many many other advantages, depending on the card.
I probably manage to get 1000 or 1500$ of rewards each year with these credit cards. And I never use more than 3 or 4 credit cards at the same time (once I get the bonus, I destroy the card).
It's a way to increase you income by at least 1000$ a year. And it only requires 30 or 60 minutes of your time.