Profile link building is regarded as spam. I have tested profile links and to be honest I didn't see a great deal of improvement in the SERPs. However, I feel this is a short term link building technique.
For thirty days straight, I built 10 to 15 profile links. At the end of the campaign, I did see the backlinks, but about two months down the road, all the links were gone. Out of the 400 links I built, only about 50 or so are valid now.
If you are going to invest time in building profile links, I wouldn't recommend it. There are much better SEO techniques that you can benefit from.