[chton]

I don't know where you get that idea. They explicitly say "some Tweets from our test partners will feature a “Buy” button", there is no mention of ads. The implication is, if I don't follow their partners, I won't see the buy button.

[Touche]

Just because you voluntarily follow the ads does it not still make them ads?

[chton]

Then any corporate accounts you follow now are 'ads'. It's an added button, no more, no less. If that magically makes an otherwise neutral tweet an ad, you need a more rigorous definition of advertisement.

[spacefight]

Until they start injecting the buy features into regular sponsored tweets. That will happen for sure.

[chton]

That's a possibility, but that still wouldn't be more intrusive than the current sponsored tweets. If anything, if this model is successful, they might even reduce the amount of sponsored stuff appearing in your timeline.

[spacefight]

A platform rejecting ad customers? Not going to happen, ever.

[chton]

"Number of ads to show" is something that can be optimized. Too much ads have a negative effect on your entire platform, so you need to strike the balance. 'As much as possible, but not too much'. If they can improve perception of their platform and improve the view-to-click ratios of their buy buttons by showing less sponsored content and rejecting customers, they will. A company always tries to find the economic optimum.