Images versus Text to increase pagerank

Is there a difference between the effects?

[crowthercm]

Hello,

If I want to create a new affiliate to a site in order to increase that affiliates pagerank, will it make a difference whether I include the other site as a graphic or text link? My experience so far seems to say that text links translate pagerank more quickly, does anyone else have this experience?

Namely, I have had some affiliates to one of my sites for about 3-4 months. They are linked only with a small 88x33 graphic file (no alternative text). In that time their pagerank has increased from 4-5. I've also created a few new sites and linked them via a text link, the effect was that they immediately jumped from 0 to pagerank 6.

Can someone help me out with understanding why? I have two theories but no empirical evidence on which one fits best:
1) Image links with no alternative text are less effective
2) New sites are easier to increase pagerank for...

or 3) i suppose which is both..

[doc_z]

PR doesn't depend on the type of link (text or image). However, ranking might depend on the type of link. (Recent thread: Text link vs picture link [webmasterworld.com].)