Most welcome sequences fail because they try to "nurture" people who already showed buying intent. My approach is to stop treating new subscribers like strangers and start treating them like people who are already halfway through a decision.
For a simple sequence, I use three emails:
Email 1 goes out immediately and confirms the problem they came for. Not a long brand story. Just, "You're here because you're trying to fix X. Here's the fastest way to understand your next step."
Email 2 goes out the next day and removes the biggest fear. For a software product, that might be setup time. For a service business, it might be price, trust, or whether the provider understands their situation.
Email 3 goes out 48 hours later and makes the decision easier with one clear action: book a call, start a trial, request a quote, or buy the entry-level offer.
One subject line that has worked surprisingly well is:
"Before you compare more options..."
It works because most buyers are not inactive. They are over-researching. That subject line enters the conversation already happening in their head. The email then says, in plain language, what to check before choosing, what mistakes to avoid, and why our offer may or may not be the right fit.
The strongest timing choice I've seen is sending the first buying-focused email within the first 24 hours, not after a long education sequence. If someone subscribes after reading a pricing page, comparison article, case study, or service page, they don't need five days of "value." They need confidence. The faster you answer the hidden objection, the faster they move from reading to buying.