How would you spend £10,000 to acquire customers?
(Or €10,000 / US $15,000 / local equivalent).
What suggests that this will generate a return?
How could you measure success?
What does cost of acquisition look like?
You may consider online advertising, traditional advertising, guerrilla marketing, a presence at expos, your own promo event, a PR campaign, hiring/outsourcing for telesales or social media, etc.
Sometimes, a startup's response to 'how do you acquire customers?' is "with social media". Without structure, this is a hand-wave, and a potentially dangerous one.
Try to be concrete about your plan, and put in place ways to measure progress - your strategy should be evidence-based as far as possible, and you should be prepared to make a judgement call if the evidence doesn't align with your expectations.
Teams - especially tech-based ones - are prone to overlooking traditional types of advertising/awareness. Make sure you cast your net wide when considering this question.