After that the communication fell silent. I resisted contacting Jonathan or David because I didn't want to appear too eager and I figured I was in a fairly strong position since they needed what I had and there didn't appear to be any other serious competitors in the space.
While on the phone I took the opportunity to ask him the burning question of why I had never heard back from them in regards to the acquisition of Preezo. I had developed my own theory which was that since Google acquisitions were known to be primarily about talent and not technology, a one-man show like Preezo would represent distinctly less value and ultimately more risk for them than if it was, for example, a team of five engineers. However, according to Jonathan that wasn't the reason as at all. It was simply that they were so busy during that time that the deal just fell through the cracks.
I gave a presentation recently at an HNLondon meetup. One of the key lessons I tried to get across is "don't be afraid to follow up".
People who do important things are almost always very busy. Everyone wants their attention, and even with the best will they don't have the time to keep track of every interaction they're involved in. In my experience, such people never get annoyed at you for following up - in fact, they almost expect it of you. The fear that "people will get annoyed at me for following up" is unfounded.
So never be afraid to follow up. The worst thing that might happen is that your email is ignored. The best thing that might happen is that you get what you want, or even more.
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