You may notice that the AddThis share counter on your page and the numbers in your analytics don’t match up. Publisher analytics, by definition, is about shares associated with a specific publisher ID. Shares from bogus publisher IDs, missing publisher IDs, misconfigured sites, etc. are all discarded.
There are also legitimate cases where multiple publisher IDs can share the same url. The share counter, being about URLs, has historically included all of those shares, including shares by people using AddThis Toolbars for various browsers. This can mean that the counter on the page may be higher than the counter on your analytics.