Native Ads, according to IAB (Interactive Advertising Bureau) are “so cohesive with the page content, assimilated into the design, and consistent with the platform behavior that the viewer simply feels that they belong.”
This can influence the behavior of the consumers as many thinks that the ad is part of the content. Google, in this pdf, says that there are two types of native ads: content recommendations and in-feed ad units. Most probably advertisers will be able to advertiser in those two places.
Know here the what Google says about the two types of native ads:
In-feed native ad units
For in-feed native ad units, it’ll take upfront time to properly create beautiful ad templates that incorporate the look and feel of your site. In addition to creative implementation, you’ll have to spend time tweaking your filters and targeting options to ensure that the ads are compelling to your users.
For custom sponsored content, you may need to spend time putting together a piece in collaboration with advertisers. Depending on the agreement with your advertisers, you may have to bake in extra time for revision requests in addition to strategically planning the core message of the piece.