if you want good quality leads then you need to do everything like start your website promotion(seo), social media optmization, email marketing, ppc .. etc.
Classifieds are effective way of generating quick leads. Then content should attract the mind of visitors.
Absolutely agree, there needs to be a full marketing funnel because even if you did SEO alone it doesnt guarantee you a sale immediately but back it up with allowing visitors to follow you on facebook for example, follow your blog (if you have one) or follow your email subscriptions, this gains social trust which in turn leads to really strong sales leads.
I think by targeting some local keywords as well the general keywords. Even 10th position on first page ranking not gives the better conversion. Get top 3 ranking for better business lead.