YouTube Ads should form one part of a broader and more holistic digital marketing strategy, complementing other marketing channels. They are awesome at building brand awareness at a very low cost and to a niche target audience. We recommend employing YouTube Ads once you have built a marketing foundation through SEO, Google Ads, display ads and social media, simply because it can help inform your the priority of your video content strategy.
YouTube Ads require a little more initial investment than other forms of marketing, as you need to create compelling content. But when done well, this investment can quickly pay itself back.