At my job, we use HeyTaco, a Slack bot. Every day you can give up to five tacos out by @mentioning somebody with a :taco: emoticon. If you answer a question or help somebody out, they will probably give you some tacos. The app keeps track of who gets the most tacos with leaderboards and the like. This has instilled a culture of helping others out on the team, by gamifying it and making it visible.
We use something like this in my org, and Google has "kudos", but I've found that the problem is their usage is highly variable even within a medium-sized or (we're roughly 1,000.) On some teams, the average employee will have hundreds of these kudos, whereas on others, the average might be 1 or 2.
This was highlighted to me recently when someone in Slack noted that one person had ~50X the kudos of everyone else and asked how that happens... and they said "just go hang around in team X's channel, they'll give you a 'taco' any time your answer a query."
Given Google's promo system (where a committee looks at candidates from very different teams) this then means they'd have to try to normalize the data for it to be useful.
At least at Google I don't think that was their original intent - the idea was to provide a way for employees to express their gratitude away from the perf context.
I don't think they should be used for perf as they are not intended to be objective feedback.
Some roles (ops, sales) are just naturally a lot more inclined to use these kinds of systems. I generalize like that after having watched similar systems at 3 companies; you hardly ever see an engineer give a "taco" for a code review, but someone in another team might give one simply for someone knowing which room a meeting is happening in. It's hard to normalize the culture. I think peer bonuses (which usually require manager approval on one or both sides) tend to be a bit more normalized across teams.
