[olliebrkr]

It's one sided. Facebook have all the data for how AcmeShop's products are selling. They are free to use this information to undercut AcmeShop's products with data AcmeShop does not have on Facebook.

Yes, it's a better deal on the face of it, but as soon as AcmeShop goes out of business, competition is gone and Facebook can charge whatever they want. And we all know from the US markets that low to no competition does not benefit the consumer in any way.

[threeseed]

None of this makes any sense.

Facebook Marketplace is a marketplace. They don't control the products that are being advertised. All they can control is the weighting of ads they run on certain products e.g. "AirPods are popular, increase ad spend to 20% of total".

But they could do this by simply optimising for ROAS just like every other company does.

If Facebook is sharing AcmeShop data with Marketplace, and it's a very big if, it would still be of almost no value.

[dgroshev]

They don't control the products that are being advertised, but they make personalised ads for Marketplace products more effective by using data they collect elsewhere. If the ads are more effective, Marketplace is better at shifting goods, undermining the competition because their competition is forced to share data with Facebook through Facebook's (not Marketplace's) market position.

[crazygringo]

I'm still not following.

Facebook isn't setting prices on Marketplace -- sellers like you and me are. We're not getting any data from AcmeShop.

When you say "Yes, it's a better deal on the face of it", I don't know what "deal" you're talking about.