If you sell one link, and Google some how know it, then I guess they will penalize I think there is no limit to how many links you can sell before getting penalized.
right u are,but why sell links if you have a pr of 5 you should be getting some decent traffic,u might as well make cash out of ppc.
if you must sell links, sell them discreetly and don't mention anything about link sell on your site. post WST here under BST without the URL and send the URL to interested people via PM. another thing to remember, sell links only to sites in related niche. that way it will be less likely for gogle to know those are paid links. putting the links on your sidebar instead of footer can also help. lots of outgoing links on the footer will make your site look like a link farm
If you sell them do it quietly, whatever you sell them for make sure its worth it if you get penalised by google. Theres no safe limit, they are not happy with a handful, they want us all not to do it.
Most of the times if you link to related sites it won't be a problem. Just don't turn your site into a link farm or something like that. Exaggerate and you will lose it.
And more than 100 outgoing links means that google does not index that page... So dont sell 100 links in footer Just kidding...
hey doing it quietly is the only solution and make sure only relevant link additions are allowed. Just blend those links into content so that it really provides less doubt that you are selling links. You can add upto 5 links. Dont do more than that. Make sure you take the offers for a long time like for a month or so coz if you are changing weekly then google will ban you.
One thing I can suggest is - if you're going to sell links, try to sell to sites that have a high PR. Or at least try not to sell to sites that have a PR of 0. A lot of good directories have requirements like this for your link to be accepted.
If google finds you selling links, your PR will sure come down to zero in the next update. Tread carefully.