You may read in poker forum or tips from the pros about keeping track of your hourly rate when you play poker. The idea behind this is to help the professional player (rounder) understand where he plays best, playing which poker game, and under what structure in regards to limits, tournaments and cash games.
Upon knowing such information a player should trend toward where his hourly rate is most profitable. For example, if a player has figured to earn an average of $ 17 an hour at the local casino playing the 2/4 limit hold'em game and compares it with his hourly rate of $ 29 multi-tabling online at the .50 / 1.00 NL hold'em tables on Full Tilt, then barring any other factors This is clearly a decision for playing online that night.
Monitoring and determining your hourly rate however at different games and locations is one of those concepts though that some new players get too caught up in and which may result in poor decisions because of it, when really they should be paying very little regard to hourly rate . Let me explain.
Professional rounds should absolutely be keeping close tabs on their hourly rate, because it is part and parcel of making good decisions in poker. It increases the odds that they will be profitable and since most prosrely on being profitable, this becomes a simple "business" decision. However for new players in the bankroll building stage, other issues are more important, like learning the game for one. Playing at the right level (usually low) lends itself to learning the more intricate portions of the game like patience, position, timed aggressiveness, and reading opponents.
Since a new player is far more prone to making errors in the game, it will reasonably cost money, but the idea is to keep that cost low while getting as much value from your bankroll as you can. This translates to playing time, which in turn builds on your ability to make the correct play at the right time. As for hourly rate, you should be paying no heed at all while bankroll building, especially if your game is multi-table tournament strategy since it may take you 50, 100, 150 or more tournaments for a substantial cash.
When you have learned enough of poker, and moved up a few levels and are firmly using OPM (other people's money) since essentially playing free poker, then you can surely adapt an hourly rate strategy into your game, but until then your hourly rate should focus on what you learn, not what you earn.