Branding: it's one of the most important things that a new company can do. It is more than simply being pretty. When done well, it says something to your customers about who you are and what you do.
Obviously, you don't want it to steal time and energy from getting to a sellable product.
Unfortunately, once you know to look, you’ll realize that many products are complete before branding is even considered. You see this over and over again in Enterprise software - up front you're shown a well designed landing page, but once you’ve shelled out the cash, you get a half working application that looks like it was built by the lowest bidder.
I'm not saying that you have to have your final brand in place, nor does having good branding alone mean you will end up with a better product. If you’ve started your own business in the past you know that the hardest part is always the selling: you need to tell the customer what your product is and how it can help them accomplish their goals. Don't just copy industry trends. Spend the time to come up with a name and an image that suits the brand you want to build.
Once you’ve taken your first step with your branding you’ll find that a lot of other choices fall into place naturally. From marketing content to UI design, you'll find that upfront investment of time in good branding will reap dividends.
If you determine your message early on you can make sure all your activities reinforce it. After all, branding is all about communicating with your prospective (and current) customers.
When you avoid thinking about branding up front, you risk speaking with different voices, and confusing your customers.