Sell product, not equity.

What? How do you possibly consider built-to-flip companies to be the "pure" startups? Wikipedia defines a startup as "a company, a partnership or temporary organization designed to search for a repeatable and scalable business model" (emphasis mine)

The "pure" startups are companies that will last for decades or more and will actually change the world, such as SpaceX and Tesla. These companies live or die on the revenue they bring in. They are real companies, not some shell built on hype like you describe (barely better than a Ponzi scheme).

Besides, even a built-to-flip company would be better off getting revenue than not. If the revenue numbers aren't high enough, keep building them higher, and don't tell them to potential acquirers until they are high enough to be impressive.

--

EDIT: The now-deleted parent comment said:

So much depends on what your goals are/how speculative your venture is.

If you're in business to make a living and build up some sort of business in the traditional sense, selling your product at a profit is probably your top priority.

Alternatively, if you've got the backing and you're just going pure "startup" where your real product is more likely to be the company itself, there is some hazard in making the upside of your efforts tangible. With actual numbers, you risk your valuation being objectively quantified rather than via hype, pro-forma speculation or traffic. Far fewer of these projects succeed, but when they do, they are likely to be the ones making the news.

And it is exactly spot on. Raising an equity round is tough, and its very "expensive" money in that it gives so much of your future success away to someone else. So when you go into your business thinking "This is the product, these are the customers, this is the market, and this is how I make money." Your need for funding is limited to getting you to cash-flow break even. Then when you have traction you may find that you want to grow quickly to capitalize on that rather than let someone else get in on the market.

So your two times you ask for money? To get to the point where you've proved the product and to get the company into self sustaining growth. And in the ideal world your seed round gets you to the first one, and your series A gets you to the second. Of course there are almost as many paths to success or failure as there are grains of sand on a beach, so there are no hard and fast "rules" about these things.

There is a great set of books for new parents, one called "What to expect when expecting" and the other "what to expect your first year" which have general sorts of guidelines about how kids develop and grow. We don't have those two equivalents for startups but they would be best sellers if we did. These books approach the problem of providing solid advice for an infinitely variable set of possibilities.

This is of course difficult to do and the dreaded chasm where most startups die. In the process you may even be categorized as gasp a small business- but some of the most successful people I know started small businesses, retained ownership, methodically grew sales to medium to large business scale, and along the way established long standing non-dilutive lending sources aka banks.