The OP asked for opinions and mine's as follows. Any effort in seeking backlinks is a waste of time. It's purpose is to artificially inflate links pointing to things normally unrankable thus not worthy of my visit. In some ways the search engine discourages link building schemes, but not many.
the result is "removed from search responses"
It is a result; probably not the result you want
If you think that links back from a useless site that google knows only exists to fake links, are worth never being in google yahoo ask, or any other SE, after about 2 weeks, go for it
Google have 80%+ of all search traffic: Google make the rules: Everone else follows along: Get a google webmaster account and follow the instructions
As written previously, buying links was something that
worked well for a while
worked: past tense; Fred assumed (Hi Fred) everyone would understand, that it doesnt work now
It's my understanding that buying and selling links is acceptable to Google, providing they don't pass PageRank. However if the intention is to influence search results then you'll be violating Google's guidelines. If (when) you get caught, don't be surprised to find your site missing from search results.
To prevent links from passing PageRank they need to be marked as 'nofollow', e.g. <a href="http://www.example.com" rel="nofollow">Click here</a>. Alternatively this can be done at page-level with the 'robots' meta tag.
Google uses 'nofollow' to help identify paid links, as do Bing and Yahoo. There are plenty of legitimate reasons for buying and selling links, such as advertising, or in exchange for goods or services. (BTW, if Microsoft would like to gift me an XBox I'd be delighted to blog about how wonderful it is).
While back links marked with nofollow have little or no SEO value, let's not forget they still have the potential to increase traffic. And if placed on highly relevant sites, you might expect to see an improvement in bounce rate - another metric that provides a strong signal - but target the wrong audience and your bounce rate will suffer horribly. So it's important to exercise a level of discretion over where links appear.
Don't buy links in bulk. If a seller offers 1000s of 'do follow' links on high PR sites, run a mile.
buying links is generally not a good idea because the number of outbound links from a website dilutes the link value. so if u buy links and the site has 10 links and then after 1 year they have sold more link to say 1000 inks the amout of link juice is less so its a short term strategy for search engine ranking
buying links is a short term solution to a long term problem. Google also looks at the outbound links from which you have links on. so i suppose those who sell links have a page they put all links. there are diminishing returns in terms of the link power u get as they add more links to a certain page. so not a good idea.