If you place them well, ie. next to other text or blend them into menu bars then I think it works much better
that's a very funny and totally UN-scientific statement no idea from where you got that. of course in link units you depend entirely on what keywords and eCPM G serves you. my stat from may 11 2007 till may 11 2008 shows precise numbers for link ads only: $10,477.46 so either you are doing something very wrong - or - I am doing something like all others do .. the choice is yours to figure out which option may be correct. the placement and colors make the difference you see my way of doing it in any of my below sig links, in my blog or any other section of my site, i have ONE style only and I use almost only ONE link unit per page so far. of course I do have some real traffic and the other adsense pay many times more in total sum than links. but the ctr/ecpm numbers for link units are among the highest ones of all but again its google to decide what value links they give you .... you however decide the topic of your pages and thus the keywords of your pages. re keywords ... depending on HOW MUCH YOU produce/create YOU alone decide on how varied your entire site and thus your entire adsense is going to be my own offline access_log stats for months of april 2007 says that I have a total of 85769 Total Search Strings used to access/FIND my site via major SE's thus the number of different keywords for adsense also may be larger than tiny hobby sites.
I think, link Units are highly effective and can help you make lots of money from your website. But you have to place them on proper location on your blog/website with same look as that of your website/blog
can't say any thing exactly but try to use proper formats and also choose the color matching to your site look 'n fill!
True for me. The fact is that to earn some money, the user must click the unit AND one ad in the result page.
Link ads have a lesser ppc but it is worth adding if it fits into your website's layout, and you can still use the regular text-ads on your webpage. It does not take a big space on your site layout.
then you must have done something VERY wrong ... we had many threads or posts about the VALUE and power of link units in much earlier times here in DP forum. if u look at my below most recent $-numbers then you see that there are many older publishers MOST successfully using link units. there are many others equally or more successful. having NO success in your case or any other's case never proves the uselessness of a technique, but only may prove that a particular method to apply a technique may have been totally wrong. those having no success in link unit use - use SEARCH function in DP forum to find older threads and then visit the successful publishers' sites to see HOW they have achieved their success.
For link units, we get payed after 2 clicks, I think that is why link units have low CTR for many people. But it is possible that link units perform better than ad units in some page or site. For example, I have a page in my site where link unit perform better than ad unit, I don't know why?