optimization so you need to be very careful at the time of link building. Evaluation of links is necessary before you start building links for your site or start selecting the right Link building Services for your website. You need to understand which links can help your site and which won't help. So question is how one can understand which link is going to help, which not?

Answer is here:

1. The site from where you are going to get links should be from same niche of your site. 2. The page from where you are going to get links should be of same niche of your site. Say an example you have loan site and if you can get a link from say mortgagexxx.com/low-rate-loan.html page then it'll be more helpful for your site. 3. Search engines should cache the page and site from where you are going to get links. If search engines haven't cache the page your site not going to get any benefit from the link. 4. Page rank: It's vital but not very important. But it's always better to get linked from Pr 2 onwards-cached pages. 5. Outbound Links: This is very important factor. If some pages have around 500 outbound links on a page and if you get link back from the site then there is a high possibility the link from that page won't be counted for your site's ranking factor. Google has a tendency of caching only first 120 outbound links. So any link position beyond that might get discounted. So always try to get link from page with lesser outbound links. Within 50-80 outbound links would be ideal, though they are on higher side, but still countable. Lesser is always better. 6. Links must be from separate class c IP’s. Search engines give less priority to those links, which are from same IP or same class c IP block. You must have seen IP as 202.56.78.101; this is just a random IP. Say you have got a link, which has IP address: 202.56.78.101. Say another link has same IP. Then search engines only count one link for ranking factor and ignore the other link. 7. Link Mortality: You should keep checking your site's link back URLs every now and then. Search engines keep looking for your sites link partners and if some of those links drop very frequently then search engines might think you have linked to bad sites and this can harm your rankings. Keep webmaster's name and email id in a database or in an excel document so that in case of any link drop you can easily charge that webmaster/owner of the site.