Sure Lot of backlinks is good for seo, but need a lot of work to create a good seo isn't not only backlinks.Unique content,Social backlink etc.
I'd say that it's not the number that counts but more the quality of the link itself. If your blog goes from 1-2 links/day to 10-20-500-etc if they are not quality/high rank then probably it will do you more harm than good.
i its all about percentage. if you have 2 bad link out of 400 its ok, but if you have 2 good out of 400 bad...
I believe if you can get your site tweeted a few times per day, you can backlink at the equivalent rate. For instance, if you get your site tweeted and retweeted 20 times/day, you are safe building 20 links/day. Google doesn't even find the backlinks all at once anyway, so if you started getting retweets and tweets today, you could start building at that same rate the very same day. I've done that with several new pages, sites, blogs, etc. and they all do well. Granted, these are on subdomains of free sites like weebly and blogspot, so they might be able to handle that a little better than say, a new domain. I use http://www.youlikehits.com/?x=209583 (my referral link from YouLikeHits ) to get tweets and retweets. Just sign up with a throwaway twitter account, then follow a bunch of people (15 per day to get 100 free bonus points). Set your payout of your tweet at 4 or 5 credits and you're off to the races. It's a bit of a hassle to do this everyday...takes me about 10 minutes everyday, but worth the effort - and it's FREE. Then, start building away.
In response to your question about how many back links a day is the best, I would strongly recommend not focusing on building back links every day, but yet, using the "content distribution" service below listed in my forum signature as a hyperlink and subscribe to it with no delay. Once you've done that, just focus on creating quality content on your blog or website and the content distribution service will do the rest, in terms of helping you build up your online traffic and increase back links to improve your search engine optimization efforts. When you focus on creating quality content and building good relationships with people online, everything else will positively, to play. If you have any additional questions, please feel free to reply, and I may possibly post the answer on my website.
I think worrying about how many links a day you build is the wrong way of thinking. More time should be put into, "How do I acquire quality links."