If you're going after "mom & pop" links, more often than not, you're wasting your time. A few related authority links will get you much farther than hundreds of ammateur site links. Authority sites are authority for a reason; these sites don't link purely for commercial means, rather for reasons that complement their webpages with 'insightful' information that they don't possess. If you can provide just that, seek them out and effectively and subtley hint that a link to you would be beneficial for your target site's audience, then you're in business!
These days, there's only so many links worth chasing after.