But back to your comment... Given 408 customers probably generated the majority of the $100M GP over the first six months of the CY and they have another 74k and change customers they've landed and have potential expand opportunities with, I'm not so sure there's no revenue there to be had.
Now that being said I think the stock will likely float to ridiculous overvaluation at IPO and all the talking heads will argue how those "band-aid" vendors have staying power through brand loyalty and proven models... But, I personally, think CloudFlare will be around as a leader in this space for a long time, especially if they continue to keep playing their cards as they have.
Those I'd expect to slowly but steadily creep up in billings since Cloudflare introduces new products all the time, they tend to be very easy and desirable for existing customers to adopt, and they tend to be upsells over the base enterprise plan.