Yeah, I’m not sure that Snapchat’s new inbox DM ads, which it’s calling “Sponsored Snaps”, are going to go down so well with Snap users.

Because as I’ve noted previously, the Snap inbox is one of the most intimate connection surfaces in all of social media, due to the privacy and protection of self-erasing Snaps, and the fact that Snapchat is not popular with adults (i.e. parents, relatives, etc.)

That makes the Snap inbox particularly sacred for younger audiences, which is the majority of Snap’s user base. And that’s why I’d be concerned about the potential negative impacts of feeding ads into this element. 
at the moment, most Snap users are seeing the first three slots of their inbox occupied by things that are not DMs from their friends.

The slots here are:

A promotion for Snapchat+
Connection to Snap's "My AI" chatbot
An ad for "Moana 2" (via Snap's ad partnership with Disney)
Notably, Snap also displays nine inbox slots on screen, in total. This means that one third of your Snap inbox is presently filled with Snap's promotions and features.

That would be a pretty big impact. And while Snap has only just begun testing Sponsored Snaps, with a limited set of ad partners, I can imagine that many of the app's 443 million daily actives are going to be annoyed by the creeping amount of promo content showing up in this feed.

Still, at the same time, it makes sense that Snap wants to try these out. A tonne of in-app activity goes on in the inbox feed, and DMs more generally are more engaging and harder to ignore. That's probably why I can already imagine a lot of marketers wanting to get their promotions into this feed, so Snapchat needs to make the most it can of its ad business, especially since it is now not growing in its top revenue markets: North America and Europe.
As such, making more money out of these audiences is key. But I’m just not sure that this is the best way for Snap to go to about it.

Still, this is just an experiment, and Snap may reverse course on these promotions and leave the inbox as is. But even if that happens, the fact it's willing to take such a risk is noteworthy in and of itself, inasmuch as Snap remains committed to finding new ways to wring ad dollars out of the app.