You definitely get the most ‘juice’ having a key phrase like this in the title but you have to balance this with how it comes across to potential customers. So my questions for you are:
– Are you selling ONLY to parents with 3 year old boys….is there a danger a parent with a 4 year old girl for example would by pass his product. Are you going too narrow? Does that last sentence read naturally or is it possible keyword stuffing? There is the option of keeping the title as it is and instead placing this key phrase in a bullet (make sure its in the first 1000 characters to ensure it indexes)
– Aside from in your PPC campaigns do you have the phrase in your bullets or elsewhere in the listing like the back end search terms? If so have you checked if you are indexing organically for the phrase ‘toys for 3 year old boys’. You can do this with the H10 keyword tracker. If you don’t have it in your listing anywhere I would start by incorporating it in your bullets (the phrasing you suggest is good!) but keep your title as is and see what happens to your organic rank as well as your PPC conversion on that Keyword.
– I would suggest you explore covering all the age permutations through back end search terms and PPC – toys for boys age 4, toys for boys age 4-8 (I know this age range to be a very valid search term from my own experience), toys for girls age 3-5 etc.
– I would also say leading up to Xmas you will get a massive uplift in visibility and hopefully conversion and these general toy search terms can be gold. Parents/grandparents/aunts/uncles are making a lot of ‘research’ searches based on the age or interest of the child they are thinking of. However you may find in Sept/Oct your ads CPC becomes more expensive and you see lower conversion due to higher impressions caused by ‘window shoppers’. Hold your nerve with PPC through that time of year to capitalise in Nov/Dec on these sort of searches.