The trick: you need to spin it as something they'd like to do anyway... you can't just present it as a way to be cool and different, you need to tie it into an existing motivation. Making money is an easy one, because then you can come in with an MLM structure, and get your cultists to go recruiting for you. You don't even need to do much in the way of developing cultic materials; there's plenty of stuff designed to indoctrinate people in anti-rational pro-cult philosophies like "the law of attraction" that are written in a way so as to appear as guides for salespeople, so your prospective cultists will pay for and perform their own indoctrination voluntarily.
I was in such a cult myself; it's tremendously effective.
If you want to reach a person who feels lonely having a community of like minded people who accept the person can be enough. You don't necessarily need stuff like money.
Change blindness is the phenomenon whereby people fail to notice changes in scenery and whatnot if they're not directed to pay attention to it. There are countless videos online demonstrating this effect (one of my favorites here, by Richard Wiseman).
One of the most audacious and famous experiments is known informally as "the door study": an experimenter asks a passerby for directions, but is interrupted by a pair of construction workers carrying an unhinged door, concealing another person whom replaces the experimenter as the door passes. Incredibly, the person giving directions rarely notices they are now talking to a completely different person. This effect was reproduced by Derren Brown on British TV (here's an amateur re-enactment).
Subsequently a pair of Swedish researchers familiar with some sleight-of-hand magic conceived a new twist on this line of research, arguably even more audacious: have participants make a choice and quietly swap that choice with something else. People not only fail to notice the change, but confabulate reasons why they had preferred the counterfeit choice (video here). They called their new paradigm "Choice Blindness".
Just recently the same Swedish researchers published a new study that is even more shocking. Rather than demonstrating choice blindness by having participants choose between two photographs, they demonstrated the same effect with moral propositions. Participants completed a survey asking them to agree or disagree with statements such as "large scale governmental surveillance of e-mail and Internet traffic ought to be forbidden as a means to combat international crime and terrorism". When they reviewed their copy of the survey their responses had been covertly changed, but 69% failed to notice at least one of two changes, and when asked to explain their answers 53% argued in favor of what they falsely believed was their original choice, when they had previously indicated the opposite moral position (study here, video here).