First-mover advantage is the benefit you get from entering a market before anyone else: the best brand name, early customers, and supply deals signed at low prices. It is real but temporary. It only lasts if you convert the head start into something durable, such as switching costs or scale.
The advantage holds in specific situations: when the market has network effects, when supply is limited and you can lock it up, when your brand name becomes the category name, or when learning curves are steep and expensive. Without those features, being first mostly means paying to educate customers who later buy from someone else.
An example. You launch 14 months before your first serious competitor. During that window, search ads in your category cost 40 euros per customer because nobody else bids, so your first 600 customers cost 24,000 euros. Two years later, with four competitors bidding, the same 600 customers would cost 110 euros each, or 66,000 euros. Your timing saved 42,000 euros, and that saving only counts if those 600 customers stayed.
The common misunderstanding is treating we are first as a strategy section. A second mover reads your website, skips your failed experiments, hires the people you trained, and builds version two while you maintain version one. Their development cost is lower than yours was.
The useful question is what you do with the head start. Sign exclusive suppliers. Build the data set. Get customers deep enough into the product that leaving costs them time. Register the trademark. Each of those turns a temporary lead into something that survives the arrival of competitors.
If you cannot name that conversion, drop the claim from your plan and compete on something you can defend.
