It depends on a lot on competition. For instance, if you top 10 competitors are building 20 links a day, your link building should be similar. If they are doing 100 links a day, you should do that too. I wouldn't say that it is risky, as it depends on many factors. Example, you publish an article that become viral or build a social network that become viral overnight and a thousand websites link to you, certainly you wont get penalty for this.