I am building a list in the weight loss niche, and to get more subscribers I bought a couple of solo ads, sent them to my opt in page and got around 42 % opt in rate. But I was wondering how good quality traffic this is. I mean, people build huge lists through solo ads and swaps and then they sell clicks, those people don't have a relationship with the list, so the subscribers probably hates him or her because of spam.
What do you think of building a list with solo ads?
Would you rather spend the money on buying facebook ads or use google adwords?