Many poker affiliate programs offer the opportunity to promote their services offline with the use of flyers and such. If you move in the right crowd, promoting a poker room this way can earn you quite a bit of money.
Even though poker associates people from all ages, the typical online player is a young male. If you are a student, in the military or involved in a team-sport, you are surrounded by potential poker players. Most probably, a few of them are already involved in online gambling, but if you handle your cards right, you can make them join a new one, so making you a commission when they play.
If you have a lot of friends somewhat interested in poker, why not suggest a weekly game? But, instead of meeting at someone's house, find an online poker room offering private tables and / or private tournaments.
Many will object to the idea, condemning it's not the same thing. They are right, it's not, but there are upsides you should point out.
You do not nee to shuffle the cards.
After a night of poker, quite a bit of time has been spent just waiting for the cards to be dealt. Online poker does not require shuffling, and the process of dealing the cards are done in a fast manner.
No more discussion of rules
In many home games, there are added rules. For people not used to them, they can be very surprising and sometimes extremely costly. With an online poker room, standard rules apply, and there is no room for discussion.
Much more poker
When attending a home game, it's not rare people get drunk, or are more interested in talking about Bob's new boyfriend, than playing cards. When you are there to play, this can be annoying to say the least.
Invite whomever you want
Home games are limited to the room you are playing in, the amount of tables etc. Online, you can automatically be any number of players, while most home games games tend to max out at 10 players or so. If some of the regular players is not housebroken, playing online takes away the problem of explaining to your wife / husband why there's beer and chips everywhere, including the children's room and in the shower.
Long lost friends can join.
If you had a game with your college friends, why not email them and invite them as well? Playing online makes it possible for anyone, anywhere to join your game.
If you are inviting your friends to play poker online, you might want to share the rewards with them. Nothing can break a friendship faster than someone cheating the other. Telling them about your plans or raising the reward eliminates this risk. If you are actively promoting the poker room to colleges, classmates or acquaints is a whole other story, that's about actually making money.
Due to the high competition of online poker, you stand a very good chance of finding an affiliate program offering good incentives for players (ie high sign up bonus, rake-back or such) and good commission for recruiting new players. Depending on who you plan to invite to the poker room, you should check out the special features available. Many poker rooms offer private tables and tournaments amongst other things.
Just inviting your friends can make you quite a bit of money, if you manage to actually promote it to a wider audience; you stand a chance of making a small fortune.