No, it wasn't a mirage... MyPoints did offer 9 MyP/$ on certain Amazon.com categories (like some clothing and some other less frecuented categories) for like 2 weeks, now it dropped to 5 MyP/$. Most mayor categories, like electronics, are usually excluded from any offers (they don't accumulate a single point).
I usually get a $100 Sears/Kmart gift card from (12.8K) MyPoints every 6-8 months w/o investing a $, just time involved. That tells you it would be even faster, depending on spending online...