On any site, voting is how the value of posts is identified and sorted. That's part of what makes the knowledge base valuable to the vast majority of readers.
But voting also plays a vital role in keeping a small site viable.
Most of the answers are created by a relatively small core of regular or periodic users. Most of these core users don't really care about Internet points on a tiny site. They answer to help other people. That can be rewarding as long as there are other people who will be helped.
When there is just a trickle of activity, answering is like the old question, "If a tree falls in the forest and nobody is there to hear it, does it make a sound?" Investing the time to write answers that go unnoticed leads to fewer answers. That creates a spiral of less reason for anyone, including the answerers, to visit the site. Voting is one of the indicators that the answers are making a sound.
Sites constantly lose members through attrition. For a site to remain viable, it needs to attract and retain new users. A trickle of people find their way here to ask a question. But that is usually a one-purpose participation.
One reason new users don't become regular participants is because of reputation barriers to participation. If they don't come from another SE site (and start with the 100 point "signing bonus"), it is hard to build the reputation to participate, even if they understand the posting rules and post good content. That's because very few of the users with the rep to vote are regularly on-site, and relatively few of those who are take the time to vote.
What can you do?
When you're on-site, take the time to vote. It only takes an extra second to click the arrow button.
And especially, if you've built a sizable amount of rep yourself but have done little voting, please return the favor by recognizing the efforts of others and by helping new contributors become participants. Heck, go on a voting spree and earn yourself some badges:
- Suffrage [30 votes in a day]
- Vox Populi [40 votes in a day]
- Civic Duty [vote 300 times]
- Electorate [vote on 600 questions]
- Sportsmanship [Upvote 100 answers on questions where an answer of yours has a positive score]
Help keep the site vital. As they used to say during elections in Chicago, "Vote early and vote often."