Our S70 was typical with appetite for lamps - until I did a simple fix. I sanded all contacts with fine garnet paper and then coated them with dilectric grease. Some of the tougher-to-reach contacts were abraded with the wire brush of a Dremmel tool instead for convenience.

This stops corrosion and likewise improves contact. The improved contact reduces "arcing" across the contacts between bulb and socket, which reduces heat stresses on filaments. Voila, longer lasting bulbs.