Expecting that volume-of-posts in social will somehow grow the top of your business's funnel could be a waste of time. But, it depends on the nature of the business and how leads are generated.
I recently read a perspective about marketing tactics that advised small businesses to ditch organic social media, as it's a time-sink and doesn't generate revenue. Instead, the author recommended to invest in SEO and paid social advertising. SEO and paid advertising are important, and work for almost any business--at least to some degree. But, I think the premise of ditching social all together as a general prescription may not be understood by some. That said, expecting that volume-of-posts in social will somehow grow the top of your business's funnel could be a waste of time. But, it depends on the nature of the business and how leads are generated. Even identical, competitive offerings can have different successes with the same tactics depending on brand and, therefore, customer types -- and it's not always the level of effort that makes the difference.
I think any small business must first ask, "what is my goal(s)" and then "where is my audience" and finally "what is the intersection (insert mental Venn diagram here) of what matters to them and my business." It may be that an essential activity is tribe-building and intermittent communication with them. If that's the case, then organic social could be a productive activity that supports generating leads or fortifying a prospect's decision-making process, leading to revenue. And, a cogent strategy would prescribe specific tasks in organic social to achieve specific goals, in order to build the business's community and, again, generate prospects or repeat business. Everyone who runs a small business knows that the two-headed beast/god of time and budget lays waste to our misguided efforts as we sacrifice our blood and sweat to grow it. So, I think it's important to remember to be careful with these finite resources and have a plan. But, also, don't be afraid to experiment, at least a little, too. From my experience, a simple tactical mix can be applied as follows:
Organic social: brand- and tribe-building to nurture existing customers and help new customers make a better-informed decision. Yes, this can generate leads, too.
SEO: grow the top of the funnel, of course. And, with the advent of voice-assisted search, there are some good, brand-building opportunities here too. This is an essential activity and should follow the three P's of: prominence, preference, and proximity (ask me if unsure).
Paid social: also growth at the top of the funnel, but with constantly tweaked algorithms, it's important to understand how each channel is rewarding ads with different CTAs. In some cases, you'll get more traction when using this in concert with #1.
Paid Search: this is also helpful to gather leads. It works with #2, also, though having a content strategy and, in some cases, dedicated landing pages can amplify effectiveness.
Email marketing: works for retention and building repeat customers. List-buying is typically less effective and costlier per customer acquisition than the other tactics mentioned here, but it is a great too for remarketing and converting prospects who are already in the funnel.