Over the past year or so of taking charge of my credit card miles and points has been a benefit to my friends as well as myself: referral bonuses. For most of the cards I currently have (which are Chase cards, incidentally) I can refer anyone to them, that person will get a link to sign up, and once they spend money on the card, I get a $50 or 5,000 point bonus. That is an incredible incentive to me (and one I have taken advantage of – if you want a referral, please let me know) as well as to the credit card company so a lot of them do it.
The big incentive for the person referred, however, is the signup bonus, which used to be smaller but now has been as high as 100,000 miles. Regular bonuses right now are between 20,000-50,000 points with spikes in the 70K or 80K level (including the current Marriott bonus of 80,000 points).
Credit card companies offer these bonuses because once people have a credit card, they usually keep it and use it. So if there is enough of a short-term benefit, the company will likely have locked in the user and be benefitting for years to come. People keep them because they don’t know better: it’s easy to keep a credit card in your wallet and use it all the time – it’s hard to keep track of multiple credit cards, canceling them when necessary and signing up again when appropriate. They often think that opening and closing accounts will hurt their credit score immeasurably – it will dip it a little but if you keep things up-to-date everywhere else, you can easily keep your score in the high 700s or low 800s (in the excellent range).
In summary: be an educated consumer. If you want to learn more and play this game to your benefit, let me know. I’ll be happy to work with you one-on-one to give you some new insight.