United’s generally worthless ‘luxury travel club’ is offering 50,000 United miles as a bonus when signing up for a 2-year membership ($500).
That’s one cent per mile, plus you get 2 lounge passes and Starwood Gold status (and a couple other minor sundry items, like the ability to request a free leather travel wallet from one of their partners).
The 3-month trial for $10, which still nets you the lounge passes and Starwood status but no miles, is still available.