I've been gaming since the early 90's, and I've always wanted to play/run more than I was. Even back in my high-school and college days, it seemed that I never got to play on a regular basis. Now, even though I am working full time, have a wife, two kids, and the million other things that go into modern life, I am gaming more than ever!
I run a game online with 5 players across 3 time zones on a weekly basis, and have been running (or playing) in these games since March 14th of 2013. In that time we've only missed 6 weeks! Even before that I was doing fairly good in 2012 with a weekly game.
One of the reason for this is that we game on-line. While there are plenty of drawbacks to online gaming and VTTs, they also remove issues of location, travel, etc. The game is always at the same place... at our computer desks. No traffic, no dealing with the need to host, none of that. Just sit and log in.
And it is almost always on the same day at the same time: Thursday's 8:30 pm (eastern). With few exceptions, we have kept to that day and time for over a year. This makes it easy for everyone to plan around the game night and try as best as we can to keep that night free. Making it a week-day and not a week-end also means fewer things "come up" out of the blue to mess with the schedule.
I have to give props to our group at being pretty dedicated and doing what they can to free up this night for our games. It isn't perfect, but everyone had done what they can and it has been working.
The last thing is that while we try to keep everything stable, we are also flexible with folks coming in late, or needing to cut out early. It is better to have a game where someone can't make it or where someone left early, than to not have the game at all. Things keep moving, the story advances, and interest in the game grows. This helps me (and I hope the others) stay motivated to keep playing and having fun.
A few other things that have helped are: Google+, I created a Group where we can post game related information or questions. All our games are scheduled using the Events system, and we run the games using Google Hangouts (with Roll20). Roll20 is another thing that has help a lot. It is hands down the best VTT I've ever used!