An acceptance is (1) a manifestation of a willingness to enter the bargain proposed by the offer (2) in a manner invited or required by the offeror.
(1) is fulfilled. But what about (2)? Did Ruth invite acceptance by silence?
Yes, that is exactly what Ruth intended. Given the five-year history, Ruth both expected and found it acceptable that HoopLA's acceptance should take the form of a lack of response.