Really not too long at all if you do your research, (make sure your competition isn't too strong), optimize your site for the keywords you're targeting, and create high quality backlinks.

Set up a couple of micro niche sites and you'll be on your way. That's where I'd start. Search around the forum. You'll find a ton of information on setting up these types of sites.

The key of the long term site is unique content and quality backlinks. You can start $5/day in less than one month if you are moving on the right direction.

Wasn't it enough to post this question twice in the main forum?

http://www.warriorforum.com/main-int...autopilot.html
http://www.warriorforum.com/main-int...autopilot.html

If you know what you're doing 30 days should be no problem at all to make $50/day. It honestly will take the same time to make $5/day as $50/day, because it will probably take near the same time to rank as the $50/day site. The only difference between the two is the amount of content and maybe the keyword selection.

How long? It depends if you pick a right keyword, low competition and build a mini-site around it. It's possible to make $5 a day in 2 months.

Please search Xfactor Forum thread. It was very helpful info.