I intentionally designed links to expire. There are several reasons for this, for example, it wouldn't be nice if someone posts a link in a "lucky" place that comes out as the first link on a google search: he would get a lot of referrals while others not. Another reason is that it would be a waste of resources if someone posts a link somewhere, his account gets completely rewarded (and then inactive until he deposits again) and he still keeps getting referrals without gaining anything from them due to the "inactive" status of his account. I think that this way is better, everyone has to actively "grow" his referrals portfolio, keeping an eye open on what happens.