If you have owned something for 85-90% of its existence and rewritten it several times while guiding its marketing and philosophy over the years, does it really matter if it was bought or started in-house? There are brick and mortar stores with similar histories, and I attribute their success to their current, long-term owners - because at a certain point maintenance and growth are far harder problems to solve than the initial MVP.
I'm sure there's a list somewhere of what's actually homegrown and what's bene bough (youtube, streetview, doubleclick, ?).