We sincerely thank you for your many years of patronage.
今後とも変わらぬご愛顧のほど、よろしくお願い申し上げます。
We humbly ask for your continued patronage in the future.
愛顧 (customer patronage or favor) sounds similar to 愛護 but refers to business patronage, not caring protection.
patronage; favor; custom
Standard kanji form. Almost always used with the honorific prefix ご as ご愛顧.
Compound of 愛 (あい, 'love, affection') and 顧 (こ, 'look back, care for'). The combination conveys the idea of caring for and continuing to support someone or something.