It’s fairly common practice for SEO companies and Internet Marketing agencies to buy links for their clients. Buying (or more accurately, renting) links on other websites using your keywords will have a positive impact on your SEO. That’s a fact. However, Google is rather against the whole process, and actively penalises websites that sell links, meaning the weight from those links that you’ve bought could disappear.
When you buy links you’re actually renting them, usually for a 12 month period. This means that when your budget runs out, or you stop paying for the links, they’re removed and your website loses the benefit from them.
It’s much better to have links that are permanent, and to get that you need content too. By updating your website with interesting content you’re encouraging others to link to your website for free, because they want to share your content. This means you could have a link from one, two, three or hundreds of websites… all for free. Plus, by adding content you could be getting links from the sort of websites that you just can’t buy links from yourself, high powered (high PageRanked if you care about that sort of thing) websites that don’t sell links.
Buying links is the quick and easy path, the path that leads to short term success and short term rewards. Adding content is a long term strategy that will strengthen your website for the long run, making it a powerful website in its own right.