The "people reached" is calculated as sum of views of non-deleted questions-threads to which you contributed a 'significant' post, where significant means (I think this is still current We're working on a new stat to help convey the reach of your posts here ):
asked the question
gave a 'significant' answer, meaning that it has a positive score (...
I think this might be an issue with Gravatar and not Stack Exchange. I'll explain my reason for thinking this later in this answer.
First off, there is possibly a way to get your old gravatar back, adapted from Caleb's answer on Meta Stack Exchange:
Go to the Wayback Machine.
Enter the URL for your profile page. If you're lucky, it's been archived there. ...
You got a recent vote on a CW answer to a very popular question, which brought your answer to a +5 score. This makes all the views on the question eligible for the impact counter.
Which is why you have such impact. If someone downvotes that answer, the number will drop by a few hundred thousands.
See also: Massive change in 'People Reached' ...
Thanks for the report!
As I mentioned in the comments, this was a side-effect of upgrading to MathJax 2.7.5. The core of the issue is described in detail over on GitHub.
Many thanks to Davide Cervone for pointing me in the right direction and suggesting a fix. It's deployed in production now. Please let me know if you see any other oddities.
You can't. Besides, your profile is meant for viewing. Usually a surge in views means that you participated or were mentioned (directly or indirectly) in a popular thread. You could check and see if something you did seems somewhat popular.
There are at least two possibilities:
Account association with an account on another SE site that itself has earned 200 rep, gives a one-time bonus of 100 rep.
A suggested edit to a question or answer, which is later approved by a user with 2000+ rep will earn the suggester 2 rep. This possibility goes away once the user reaches 2000 rep -- auto-approved ...
Some of the new styles on the page caused the rendered MathJax to be rendered in the incorrect position (and also hid it).
You could see that as a flicker of the page, seeing the rendered MathJax (in the wrong position), which then suddenly disappeared.
I also added the missing re-rendering when changing the sorting & filtering.
A brief answer is that you should go to your profile and click on the number of consecutive days. (Remember that you'll find this in the profile tab, not in the activity tab.)
You can find more details here:
Statistics of visits on M.SE
Implementation date for the consecutive days calendar
How can I see which days I visited site?
The tag-info for the ...
The information labeled private in your profile (including your email address) is visible only to you, to the moderators (those with a diamond sign), and some of SE employees (namely, those with a diamond on Math site).
You can check this yourself by viewing your profile from another browser or computer on which you are not logged in to SE (or from ...
The overall count includes your votes on deleted posts. The tab with details of your votes doesn't.
Back in the days, the overall count did not include votes on deleted posts. That was changed last year: "Votes cast" should include votes on deleted contributions. One reason is that the votes cast by a user on deleted posts are still contributions ...
The use-case seems marginal to me, so I do not see a need to have it on the profile, but if you want to know just use search: "user:me wiki:yes" will return all your CW posts; you can further refine the query in various ways.
Side note in view of comments: you would also note major amounts of up-votes arriving via badges.
According to this answer at meta.SO it stands for any activity, but it is updated at most once in 30 minutes. (My guess is that the frequency has been increased since then.)
More relevant meta.SO threads:
What determines when a user was "seen"?
A user "seen" 12mins ago but posted a question 9 mins ago. How?
Is "seen" working ok?
You can find more ...
When you click your own profile, the default tab is the activity tab. You should go to the "Profile" tab, where you can see the "visited $x$ days, $y$ consecutive" text. Click this text to show the calendar.
Quoting Haney's answer from Meta Stack Exchange:
Thanks for bringing this up. We made a change to our SQL server configuration that caused our logins to fail, which meant the data driving our sites was inaccessible (thus the errors). We've fixed that error and things should now be working properly. Sorry for the inconvenience!
A quote from Greg Bray, ...
This behaviour change is a result of implementing Fix UI of the Reputation Tab Rows. Unfortunately, it seems you're in the "only the triangle should activate expansion" camp, and the other ticket's OP is in the "clicking anywhere in the row should activate expansion" camp.
Our Markdown help's expandable sections also expand when clicking on the title, not ...
Why did "Recent Names" disappear from the Profile View?
It is still there; it only shows for your own account unless you are a moderator, and only shows if there is something to report - i.e. a name change in the last 90 days. Looking in history, it looks like it has always been this way, or at least since the user-profile pages were updated (4 months ago).
I just noticed that the formulation has been changed:
(On main, only the part about answers is in the tooltip.)
In addition to fixing this bug, it now also includes the total score for the non-wiki questions you asked.
If I speculate a bit, this opens up potential for new badges.
It's the list of tags in which the user participated. The score is the aggregated score of all non-wiki answers in the particular tag. The number in the multiplier is the number of all non-wiki posts (questions and answers) in that tag.