Update: Some offers mentioned below are no longer available – United MileagePlus Explorer CardThroughout the month of October, United’s been offering MileagePlus members the opportunity to earn some pretty substantial bonuses when purchasing products at select retailers with United MileagePlus Shopping. The carrier has offered day-only bonuses, as well as some that have spanned a few days. To finish out the month, the airline is offering one last round of elevated bonuses on five merchants.The one-day increase is taking place today, October 27, and you can earn 15 miles per dollar when you go through the portal and shop with one of the following five retailers:Sephora (normally 3 miles per dollar)Brookstone (normally 3 miles per dollar)Groupon (normally 2 miles per dollar)Lord & Taylor (normally 3 miles per dollar)World Market (normally 2 miles per dollar)Based on TPG’s latest valuations, earning 15 miles per dollar will get you a return of 22.5%. In addition to these one-day-only bonuses, note that your time to sign up for the United MileagePlus Shopping Sweepstakes is limited. Through the end of the month, you can sign up to win a grand prize of 100,000 miles and $2,500 cash, plus three first prizes of 20,000 miles each. To register, use this link and you’ll get one entry to the contest. You’ll get an additional five entries when you sign up for marketing emails in addition to another five entries for each qualifying purchase of $50 or more (up to 25 entries per day).In addition to these one-day bonuses at the aforementioned five retailers, keep in mind that you could also be eligible for increased bonuses at other retailers for being a United co-branded cardholder, for example the United MileagePlus Explorer Card. If you’re not already a cardholder but would like to become one, the card comes with a sign-up bonus of 40,000 miles after you spend $2,000 in the first three months.Bottom LineSign up for our daily newsletterEmail addressSign upI would like to subscribe to The Points Guy newsletters and special email promotions. The Points Guy will not share or sell your email. See privacy policy.If you’ve been planning to make a purchase at any of these five retailers, today’s a great day to do so online by going through the MileagePlus Shopping portal. The bonus miles per dollar for a total of 15 are enough to go out of your way to purchase through the portal, and earning the bonus miles can help put you on your way to your next award redemption.[card card-name=‘United MileagePlus® Explorer Card’ card-id=‘221210146’ type=‘javascript’ bullet-id=‘1’]