When I bought my house, it was obvious the previous owners/tenants had used cheap fiberglass filters, as the blower fan and motor had a layer of gunky dust a quarter inch thick (this house was a repo).
With a good cleaning, the blower and motor were in good shape again, but I wanted to make sure they stayed that way. Filtrete filters will ensure that my whole system stays clean.....I just wish they could speak, and give me a reminder every month!