After receiving numerous link exchange request on some of my sites. I've decided to write a guide if you want your site to be accepted in a link exchange. First of all if you're just building an MFA sites the percentage that your site will be accepted is around 10 to 20 %. Then why should you spend creating a Made-for-Ads/Adsense (MFA) sites if your site will just be rejected and will not rank in SERP absolutely. But if your intention is to spam to get traffic then it's a different scenario. (This is black hat SEO technique and will be penalized by Search Engine soon)
Nowadays I've seen lot of crap sites. When I say crap sites it means the site's content is ripped off from another site.
There are some ways how to know if a site's content is ripped off from other site just copy a part of the article and paste it in google then it will show results relevant to your site.
Should I go for automatic link exchange software?
The answer is no. The only chances that your site will be accepted are webmaster that don't know much about SEO. And usually the site is garbage and the owner is not serious on his site.
Also make sure you are dealing with trusted person. Because most of the time when I'm dealing with someone after few weeks my link is removed or been placed to page in his/her site that cannot be accesed through homepage.
As always do not link exchange with "bad neighborhood" porno and pharmacy related sites are one of them. It will surely hurt your site's rankings in SERP if you will link back to these sites.
Should I go for Higher PR sites?
Yes, but make sure you are linking to a relevant sites as well. Again quantity vs quality is the issue here. I suggest you choose quality because this is the most important in link building.
Why should I go for higher PR sites?
Simply because higher PR is loved by Google. Meaning more spiders will visit your site. The more spiders the highest the percentage that your site will be indexed fast. And soon the rankings will improve also. But definitely PR isn't directly related in SERP. It doesn't imply that the higher the PR the higher the rankings in SERP. This is the common SEO myth.
Also I want to give you what Mattcutts think on link exchange.
" The best links are not paid, or exchanged after out-of-the-blue emails–the best links are earned and given by choice. "
So it's better make your site more useful so that people will voluntary link to you.