I joined in and get a few link request. But I could find where they put my links and linkmarket said they check it and urge me to put those requster's line on my site. How could I know it is true or not?
I use linkmarket. but always decide for yourself if you want to trade. I've seen a lot of sites in the linkmarket directory with high rankings that request a link exchange but put your link on a page that is not index by any search engines and has 0 visitors (no links to the link page, robots.txt that's blocking it etc.)
for google: just enter the complete url in the search box. like this: http://www.google.com/search?hl=en&lr=&q=http://www.linkmarket.net/ and compare that with a url that is not (yet) indexed: http://www.google.com/search?hl=en&lr=&q=http://www.linkmarket.net/blah
I use linkmarket. Within 3 months of opening we hit a PR4. I would highly advise on getting there paid account. Its $25 and well worth it. You can see what PR sites you are tradeing with. You could just exchange with the PR5/6/7 if you wished. Best of luck.
Yeah, the best thing to do is get the paid account, you can see all kind of stuff the free acounts can't, and you also get the chance of restricting the kind of sites that can ask for link trades with you, so you don't end up getting bombed by gambling or similar trade requests.