The first line is not a greeting, it is the start of the path to an order
Someone arriving from an ad still has the product, the problem or the promise in mind. The first reply has to pick that up, so they can see immediately that you understood why they came — rather than a generic welcome unrelated to the ad they just watched.
A good first line is one that is easy to answer.
A three-step formula for a natural opening
Confirm the source or the need. Lower the pressure in one sentence. Ask exactly one easy question. For example: Hi — I see you're looking at acne care. So I don't recommend the wrong thing, can I check one thing: is it mostly recurring breakouts, or the marks they leave behind?
Three mistakes that make customers go quiet
Do not send the full catalogue, do not chain personal questions, and do not quote a price before you understand the need. More information is not more professional. The goal of the first exchange is simply that they keep talking.
Give every answer a defined next step
Prepare the follow-up question, the recommendation condition and the handoff rule for each common answer. Then a salesperson or an AI can continue along the same logic.