When you're in the reporting page and you look at your Visitor Vote report, you'll notice that the total vote count may be different than the number of users who "want" a request on the individual request page.
Visitor vote report:

Request page:
The number of votes in the reporting area can vary based on the filters that are applied on the right-hand side.
The default popular vote report includes active, paying visitors only. It does not count any team votes.
You can adjust the 'Advanced' Account Filters on the right-hand side to include all visitors:

Just select "Any" under Account Status, Account Value and Account Activity to see all visitor votes. Note that this report will still return visitor votes only; team votes are not included.
You can also dig down into request demand by tweaking the filters on the request page.
On the request page, click "Filters" in the Request activity section:

Then adjust the filters to see demand from the Visitors or Accounts you are interested in.