Let's look at some reasons a referral might stop clicking?
If a referral is under the impression he or she will make a lot of money, it is easy for them to get discouraged and stop visiting.
If their anti-virus sounds an alarm, even if it is false, they might decide to stop visiting.
After seeing ad after ad for more PTC, or other programs wanting them to join, they might become discouraged or just bored and stop visiting.
If the person that recruited them never communicates with them, they might think they are only another number and stop visiting.
If a referral figures out that the only way to make big money (thousands per month) is to recruit, especially after being told they do not need to recruit to make money, they might stop visiting. This is more true if the referral is not one that likes to recruit, or is not good at recruiting.
I am not saying you are guilty of anything. Nor am I trying to blame you. I am just speaking from my feelings. I am the exception. I still click even though I have no referrals, I never hear from my upline or other "perks".