I started davespornplace in August, 2008 and pregnantpornfan in October, 2008.
In the past year, I've been spending my free time developing iPhone apps and I have done almost nothing with these adult sites.
Davespornplace is a collection of freesites, 5 BBW, 5 granny, and 4 pregnant. I built the freesites myself from scratch. Some of them are copied from others, so there are probably 5 or 6 unique designs that could be re-used to add more sites.
At one point, I was working on turning it into a linked list, so I have a very basic mysql database setup and a basic php submit form for webmasters to add their sites to the main page, which is separated by niche.
When I was actively working on the site and adding freesites, I had between 8k and 17k uniques each month. Now that I haven't touched it in a long time, it's been between 2k and 3k per month.
Pregnantpornfan is being used for a pregnant blog that currently has 31 posts, all handwritten, with pics or videos. This site has been up to about 2500 uniques per month, and has been a little over 1000 uniques per month lately, with virtually no updates.
I think these sites would be a good starting point for someone wanting to get into the business without starting from scratch. I just never had the time to grow them.
http://www.davespornplace.com
http://blog.pregnantpornfan.com
If you're interested, PM me with an offer.