I have been controlling today the link exchanges I did in the past and found that an high percentage of them are not posted in the sites of other members... The question is how many time do you control that your link exchanges are working? I must admit that I will only accept link exchange with members with high itrades....I think its the only way to not be scammed....
I have tool which allow me check backlinks for a site and then save the report and you can compare two reports for alteration. Well, I check it once or twice in a month.