I use linkmarket.com to exchange links. I would like to add Google ad sense soon and I don't know does Google likes this king of links exchange?
no, i dont think google "likes" link exchanges... from the webmaster guidelines: "Don't participate in link schemes designed to increase your site's ranking or PageRank. " and on their page that describes what link schemes are: "Excessive reciprocal links or excessive link exchanging ("Link to me and I'll link to you.")"
As far as I know google doesnt like bought links in the page, but if You want to sell links, do it for related sites. i think google will not consider them as bought links.
If the links are relevant to each other, most likely OK. Don't blindly accept link exchange from non-relevance sites.
If you look at the facts and not opinion you can get a clearer and more realistic answer to this question. Fact 1 Link market is indexed by Google. "Results 1 - 100 of about 83,500,000 English†Fact 2 The websites that trade there are index by Google. Fact 3 Link market has Pagerank Bad neighbors exist on the internet. I have used Link Market and have received allot of link request because of my PageRank. It’s just like anywhere else. Turn down the ones that are bad neighbors. Take the time to investigate the person you want to network with. If you look to the long term in building your website you will make more responsible decisions. Be careful who you trade with. Their is no easy way to build a quality website other then putting in the time.