who was mr pumblechook? why did he want to take pip to miss havisham?

"Mr. Pumblechook is Joe’s uncle, but Mrs. Joe considers him to be one of her BFFs. He is the local seedsman (he sells seeds and stuff) and is charged with escorting Pip to Miss Havisham’s house for the first time. Because of this, Mr. Pumblechook believes forevermore that he had a big hand in helping Pip to his fortune. He tells everyone he meets this, and Pip is thoroughly annoyed with him because, as he brags, Joe is silent. He hordes food, he’s greedy, and he likes to pour water into Pip’s milk. Orlick eventually breaks into Mr. Pumblechook’s house, ties him up, sticks flowers in his mouth, and robs him."

http://www.shmoop.com/great-expectations/mr-pumblechook.html

Miss Havisham hears of Pip through Mr. Pumblechook.