I know it's only 1 more than the 4 I got last week, but I think it's significant because it proves that last week wasn't just a fluke. This customer came after I made another post on IndieHackers.
Seeing that there's a connection between writing a post that promotes TweetSpacer and getting a new customer is a strong signal that I'm moving in the right direction. it suggets that this is product that people want and I'm promoting it in the right place to attract those people. Now I just need to optimize where and how I promote it and make the product better and better for my existing customers.