How do you differentiate Busy from competitors like Buffer (with its 69 employees, according to Wikipedia)?
btw, there is a small typo on your "How it works" page: "secure and: affordable" should just be "secure and affordable". :)
Buffer: I haven't done much in terms of "battling" with competition, simply because my users will tell me what they want, and that's an easier crowd to serve than trying to follow a competitor who may be running down the wrong path without knowing yet. If a bunch of users ask me for the same feature multiple times, then I look into what it takes to make it happen, or I'll explain why I can't offer that, and that's what's been driving it from day one.
Thanks for your note about the typo, I am actually always a bit ashamed of my landing pages, because they feel the least fun to make (to me at least), when they drive most of the conversion of course.