What will generate more traffic, a Wordpress website or Custom Built PHP not open source?

[theBrewRoom]

When it comes down to it, there is no difference when it comes to generating traffic to your site.
It is really 100% dependent on the content of your site, and how promote it.

Search Engine Optimization has a LOT more to do with it than the type of content management system that you use. It has everything to do with the content of your site, and on each specific page of the site. Yes, speed is a factor in how you site is ranked, but if you don't use someone like GoDaddy and use a more reputable host, then you won't have any worries there.

WordPress makes is VERY easy to optimize your site for it to be found by search engines. It's really up to you to do the work to make it rank well for the search terms that you want it to rank for. There's a lot of work in order to do that. It doesn't just happen overnight.

I just posted a blog about SEO and WordPress, you should check it out:
http://thebrewroom.com/seo-for-wordpress/
You might also want to take a look at some SEO tutorials that will show you what the basic important factors are. Here's a good one:
http://www.seomoz.org/learn-seo

Hope that helps!!!