One big question that SEOs are asking: what effects will Google Instant have on search marketing?

As you may have noticed, Google can now predict your search query and offer up potentially relevant sites as you type, a change which could affect the search world in a few different ways...

How will Google Instant affect search behaviour?

My view is that that the overall affect is going to depend on how quickly Google can display search results as you type.

It seems to take a little under half a second to display results at the moment, which isn't quick enough to stop me typing in a longer query. Faster typists will be less affected, so I would imagine that younger, more computer-literate users will end up typing in the term that they originally intended most of the time anyway. And, if it only applies to users searching from the Google homepage, rather than a toolbar, the effect will be lessened further.

What about the search suggestions box?

The addition of the search suggestions dropdown box could influence search behaviour, with users selecting one of the suggestions displayed. I had imagined that a user might intend to type 'acme anvils', but end up typing an exact product name when they realised that they could be more specific. However, the options displayed are still quite generic, so I can't imagine this changing too much.

I think the main effect this will have is to reduce returns from lower SEO positions, as all the results on the page are pushed further down the page by the suggestion dropdown menu. Those sites in positions 3-6 could end up with reduced CTR as they are pushed below the fold.

That said, Google's Matt Cutts commented that he ended up typing in a longer tail query which resulted in him clicking on a natural result that would have otherwise been on page 2, so this will probably depend on the nature of the query.

CTR in PPC will be affected, but as it's the same for all advertisers I can't see it affecting CPCs, unless you are displaying ads in positions further down the page than 4-5 as, again, these will be pushed further down the page by the suggestion box.

My initial predictions for search traffic:

1. Less traffic from PPC ads in positions lower down the page than 5
2. Less traffic from SEO results in positions lower than 3-6
3. Less traffic from long-tail keywords for users in older/less computer literate demographics
4. More traffic from long-tail keywords from younger/more computer literate users, or those with slower connections
5. More traffic from PPC ads in positions higher than 5
6. Smaller businesses may be squeezed out in certain circumstances

All of the above will probably differ, depending on the nature of the query (searching for information, or searching for products/services).

Finally, it will become valuable to see separate Analytics data for users searching on the Google homepage versus those searching from a toolbar. I wonder if Google will offer this?