Al Qaida evidently blundered when it initiated terror operations in Saudi Arabia. It must have thought that the high density of Islamists and other sympathizers in the Saudi population would be moved by their boldness to rise up with them in revolt against the Royal family. That didn't happen. Instead it seems that many Saudi's, although sympathetic with al Qaida's aims of getting the United States out of Dar al Islam, resent al Qaida's means for accomplishing that goal.
Now al Qaida finds itself with fewer and fewer safe havens as this Strategy Page account of recent developments in Saudi Arabia makes clear. The Saudi's drew up a list of twenty six most wanted terrorists a couple of years ago. Only three remain at large.
