The key word for me when building social media followers is 'quality'. So often with this challenge, another 'q' word is used...'quick'. Unfortunately, with social media followers, the two words are not always synonymous.
I have often experienced pressure from clients to build a volume of social media followers 'quickly'. In my opinion, this is short-sighted - unless the overall objective is to create a 'vanity tool' i.e. the impression of a huge fan base rather than the reality. If speed/vanity is the ultimate goal then buying followers is the route. However, in my opinion, this is social media suicide. It's not real, it won't result in engagement and it certainly won't translate into commercial results.
Alongside patience, the key to building a quality social media following is listening to your customers. For me, this is the key for most marketing channels, but no more so than social media. Ultimately, social media is a pastime. It's a thing we do to entertain, distract or stimulate ourselves. Therefore, we want to see content that's interesting, engaging, relevant, thought-provoking, aspirational, identifiable, challenging - so in summary: really good!
Therefore, the key to building a quality social media following is to publish excellent content. At Salt (my agency), our ethos is to always ask ''will the target customer like this content?''. It sounds simple, but this customer-centric thinking means the content we curate is of a high quality and appeals to the following we're trying to attract. Tactical and careful use of hashtags, promotion and influencers will all help to support this strategy.
For me, at the heart of building a quality social media audience is excellent, customer-centric content. It's not a silver bullet, and it might not be quick (it might be!) but it will ensure an engaged, relevant, supportive and quality following.