"This data is limited to static, optional Google+ Profile fields including name, email address, occupation, gender and age."
It is also including a lot more than what they said above:
The json per profile is as follows:
{ "kind": "plus#person", "etag": etag, "nickname": string, "occupation": string, "skills": string, "birthday": string, "gender": string, "emails": [ { "value": string, "type": string } ], "urls": [ { "value": string, "type": string, "label": string } ], "objectType": string, "id": string, "displayName": string, "name": { "formatted": string, "familyName": string, "givenName": string, "middleName": string, "honorificPrefix": string, "honorificSuffix": string }, "tagline": string, "braggingRights": string, "aboutMe": string, "relationshipStatus": string, "url": string, "image": { "url": string,
},
"organizations": [
{
"name": string,
"department": string,
"title": string,
"type": string,
"startDate": string,
"endDate": string,
"location": string,
"description": string,
"primary": boolean
}
],
"placesLived": [
{
"value": string,
"primary": boolean
}
],
"isPlusUser": boolean,
"language": string,
"ageRange": {
"min": integer,
"max": integer
},
"plusOneCount": integer,
"circledByCount": integer,
"verified": boolean,
"cover": {
"layout": string,
"coverPhoto": {
"url": string,
"height": integer,
"width": integer
},
"coverInfo": {
"topImageOffset": integer,
"leftImageOffset": integer
}
},
"domain": string
}(from https://developers.google.com/+/web/api/rest/latest/people)