When we launched Basecamp, we didn’t even have the ability to bill customers! Because the product billed in monthly cycles, we knew we had a thirty-day gap to figure it out. So we used the time before launch to solve more urgent problems that actually mattered on day one. Day 30 could wait.
You have no idea how many times we've managed to convince our clients to wait to do Y until after we launch X. When faced with this predicament... ask yourself, "Can we get by without X? Can we get by without Y?" Get the necessities to market first and let nature take it's course.