I am planning to buy traffic from expired domains, does this kind of traffic not against adsense TOS?
Buying traffic is against the TOS as it is artificial. It is normally pointless traffic as well as it is untargeted and could in most cases be bots or autosurf programmes which would also be against TOS. Basically, there is too much risk involved in buying traffic.
Text link sales? Get other people to display your site's link or image on their website(s). In turn, your search engine ratings will increase, and possibly your hits.
Concentrating on building your website as well as promoting it will bring more visitors in the long run. Submitting to directories, writing and distributing articles as well as getting links from other websites will all help your website become more visible and accessible by search engine spiders (in the form of providing one-way links to your website). It will then depend on how competitive your keywords and how good your content is whether people will find you and then stay with you. There is no overnight traffic paradise - it is generally a long process of constantly building up links and site content that eventually gets you noticed. There are a few websites that arrive and get some great exposure that drives traffic to them - however, this will not happen if there is nothing different about your website.
If that consider as artificial traffic, what you call those sites using adwords to promote their MFA sites with out real content but all ads. I am sure most of you see already those kind of sites. But why google allow them to do that?