Here are some useful facts straight from wiki
Online venues, by contrast, are dramatically cheaper because they have much smaller overhead costs. For example, adding another table does not take up valuable space like it would for a brick and mortar casino. Online poker rooms also allow the players to play for low stakes (as low as 1¢/2¢) and often offer poker freeroll tournaments (where there is no entry fee), attracting beginners and/or less wealthy clientele.
How online poker rooms profit
Typically, online poker rooms generate the bulk of their revenue via four methods. First, there is the rake. Rake is collected from most real money ring game pots. The rake is normally calculated as a percentage of the pot based on a sliding scale and capped at some maximum fee. Each online poker room determines its own rake structure. Since the expenses for running an online poker table are smaller than those for running a live poker table, rake in most online poker rooms is much smaller than its brick and mortar counterpart.
Second, hands played in pre-scheduled multi-table and impromptu sit-and-go tournaments are not raked, but rather an entry fee around five to ten percent of the tournament buy-in is added to the entry cost of the tournament. These two are usually specified in the tournament details as, e.g., $20+$2 ($20 represents the buy-in that goes into the prize pool and $2 represents the entry fee, de facto rake). Unlike real casino tournaments, online tournaments do not deduct dealer tips and other expenses from the prize pool.
Third, some online poker sites also offer games like blackjack or side bets on poker hands where the player plays against “the house” for real money. The odds are in the house’s favor in these games, thus producing a profit for the house. Some sites go as far as getting affiliated with online casinos, or even integrating them into the poker room software.
Fourth, like almost all institutions that hold money, online poker sites invest the money that players deposit. Regulations in most jurisdictions exist in an effort to limit the sort of risks sites can take with their clients’ money. However, since the sites do not have to pay interest on players’ bankrolls even low-risk investments can be a significant source of revenue.
Now why is it so much fun!
Online version of poker has several great advantages compared to the traditional one. First of all, it’s much quicker and you don’t have to wait for others as long as when you are sitting behind the table. It has been measured that average online poker hand is twice faster than regular one. There is no time wasted on dealing and mixing the cards. Next advantage of online version is its availability. There are thousands of servers which provide this service and you can always find people online to play with.
If your looking to try Online Poker I’d try Online poker rooms