lexipixel - 11:05 am on Jan 4, 2012 (gmt 0)
eBay. I had a nice little auction program I wrote for a BBS platform before the web.
If I only know then what I know now...
I also developed a shopping cart script very early on, then gave up development and started using other people's scripts to build other people's ecommerce sites.
I would have focused development time on my own scripts and geared things toward SaaS instead of software "distributions".
In general, I would have never built anyone else a website and instead would have only worked on building things that I own and had the potential for residual income.
I would not have EVER created Farmville or anything where you could throw a chicken or poke someone.