Marriott Rewards (including Ritz-Carlton) - newbie platinum question, earning miles

I'm on a platinum challenge and have a two week stay upcoming at a RI for starters. I've read various threads about Q3 promotions/bonuses that say you had to sign up by 6/30.

If I switch to earning miles, are there any megamiles opportunities out there for UA (or WN)? Based on my spend, it looks like 5x points will be better than 1x miles unless I can find some promos to maximize those miles.

Thanks

I'm on a platinum challenge and have a two week stay upcoming at a RI for starters. I've read various threads about Q3 promotions/bonuses that say you had to sign up by 6/30.

If I switch to earning miles, are there any megamiles opportunities out there for UA (or WN)? Based on my spend, it looks like 5x points will be better than 1x miles unless I can find some promos to maximize those miles.

Thanks

Marriott has a promotion called Mega Miles. Triple your normal airlines miles between now and Oct 31st. Great promotion. Check it out.
https://www.marriott.com/rewards/promotion.mi?promotion=MMF2

excellent, thank you. I previously thought 6/30 was the deadline for sign up.