You can also ask @Jerryll Noorden, SEO expert.

I've researched doing postcards, SEO, bill boards, and even radio ads; is anyone doing these and are they effective?

I do SEO COMPLETELY different from anyone and everyone else.

Use any combo of the above and mail or cold call.Other methods are driving for dollars, door knocking, wholesalers, craigslist, Realtors, FSBO sites, expired listings, put out bandit signs, billboards, newspapers, other offline publications.You can use pay per click/adwords, motivated seller website with SEO, facebook, Linkedin, Youtube, and other forms of online and social media marketing.

I need to become an seo god

I spoke to an investor yesterday that purchased a proprietary SEO package for $50k.

LEADS = SEO (DMM/PPC/...) + CREDIBILITY

We hired an SEO company for organic search results, but while waiting for this to kick in, I started my own Google Adwords campaign.

It requires a HUGE effort (and/or some money paid for a service) to do all the things necessary to KEEP your site in the high rankings.Great SEO in the page itself will continue to work, however.  

Our 2 biggest marketing channels are website using Seo and pay per click, and direct mail.