I've been impressed with http://subscriptiongenius.com. Best of luck to you with this endeavor!

Perhaps there's another angle to approach this: "How have startups encouraged and enhanced the power of Google?" Since inception, Google has acquired over 100 companies—many of which would be considered startups. These M&A's are a way for a large company like Google to onboard talent and IP that enhance existing products as well as extend their offerings. An example would be the acquisition of GrandCentral which ultimately became GoogleVoice. They have also acquired several smaller search engines that have gone on to enhance their core offering, as well as protect their market share.

The best time to begin incorporating identity strategy into the mix is when the vision for the product is clear. If you can clearly articulate what you are building, the key features, the environment you are attempting to create, and who your target customers are, you're ready. Here's the good news—quality brand and identity advice and visual design does not have to be very expensive. I've worked with large agencies and freelance experts in the past, and the only difference I have experienced is the cost. Wishing you much success!