Google doesn't like seeing pointless or bloated toolbars in its Chrome Web browser, and because it loves us so much, it doesn't want us to see them, either. Google's policies have long prohibited most types of truly offensive extensions, like ad-ridden toolbars, but beginning next summer, it's going to enforce some new policies that will drastically reduce the number of multi-focused toolbars and extensions.
In effect, Google will allow toolbars or extensions that have a singular focus, and it appears that it's going to prohibit developers from injecting ads into their toolbars. If they do, that has to be the sole purpose of the extension, and of course no one will download that.
I haven't given it much thought, but I do happen to use one Chrome plugin that injects ads. "Auto Refresh Plus" is just as it sounds; I often use it when keeping pegged to a Reddit thread discussing some ongoing sports event. The downside is that on some websites, an ad will be injected - that's how the developer has chosen to monetize, and because I rarely notice it, it hasn't bothered me too much.
But with these policy changes, it seems that this plugin will have to cease that kind of monetization. Based on Google's wording, it seems like most developers who want to earn money from their extension will have to go the route of pleading for donations, as that can be done through the "What's New" page or something similar.
For consumers, these changes seem good overall, though it does mean some will have to run more extensions due to Google not wanting multi-purpose extensions on its store at all. While developers could still produce such extensions, it would have to be grabbed from the developer's website, manually installed, and manually updated.
There is a downside to all of this: Google's overseeing its Web store with an iron fist, and what it wants, goes. Many users might enjoy the extensions they use that have multiple purposes, but that doesn't much matter to Google. It'll be interesting to see how these changes go down, both on the developer and user sides.