I have seen quite a few people buying xrumer and senuke backlink blasts here. Well, I am a full time optimizer since 8 years and run my own business. Here is what I think you MUST read before screwing your own website.
1. Basic
More the number of backlinks = better your rankings = WRONG.
Relevancy is the key guys. If a same niche website is linking to your site, that is the time it will have a little juice. But having thousands of links that are just spam, you are digging your own grave.
2. Frequency:
A website that hardly had 10 backlinks, just within a day, it reached on 1000's of backlinks, do you think that will help? NO! That will get your own ranking screwed. Google algo is very powerful when it comes to the frequency check. A website that has 10 backlinks after 4 months, might get 10-12 more backlinks a month. But having 1000's of links all of a sudden will get you banned or sandboxed.
3. Logic:
So your links are posted on thousands of forums and website with anchor'ed text! WOW! [NOT]
Well, I really don't have word to explain the ignorance of logic here. If a forum is allowing you to post spam, do you think you're the only one spamming there? That forum will have thousands of spam thread. Which means, that forum doesn't have any juice and google is already not considering its backlinks.
Now you having link from that forum will put you down too. As you are passively being linked from someone who doesn't stand anything. In fact, is a spam-full-board.
Hope that made sense to you. These were just my 2 cents. Couldn't resist myself typing this after I saw many people falling for xrumer and senuke.
Thanks.