In my experience, the most profitable backlinks share a few characteristics: they come from sites in your industry/niche, they're placed contextually within relevant content (not just sidebar links), they drive actual referral traffic, and they come from sites with decent authority metrics. Instead of obsessing over quantity, focus on these quality factors. Just be wary of any service promising hundreds of links cheaply - that's a recipe for a Google penalty! The links that will truly help your business are those that put you in front of potential customers, not just search engines.